diff --git a/.travis.yml b/.travis.yml
index 60086e6e..3a94e663 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -29,7 +29,7 @@ jobs:
       php: 7.1
       script:
         - ./vendor/bin/php-cs-fixer fix --diff --verbose --dry-run
-        - ./vendor/bin/phpcs --report-width=200 --report-summary  --report-full samples/ src/ tests/ --ignore=samples/Header.php --standard=PSR2 -n
+        - ./vendor/bin/phpcs --report-width=200 samples/ src/ tests/ --ignore=samples/Header.php --standard=PSR2 -n
 
     - stage: Coverage
       php: 7.1
diff --git a/composer.json b/composer.json
index 96cc5225..4a087075 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,7 @@
     "scripts": {
         "check": [
             "php-cs-fixer fix --ansi --dry-run --diff",
-            "phpcs --report-width=200 --report-summary  --report-full samples/ src/ tests/ --ignore=samples/Header.php --standard=PSR2 -n",
+            "phpcs --report-width=200 samples/ src/ tests/ --ignore=samples/Header.php --standard=PSR2 -n",
             "phpunit --color=always"
         ],
         "fix": [
@@ -51,12 +51,12 @@
     },
     "require-dev": {
         "tecnickcom/tcpdf": "^6.2",
-        "squizlabs/php_codesniffer": "^2.7",
         "phpunit/phpunit": "^5.7",
         "dompdf/dompdf": "^0.8.0",
         "mpdf/mpdf": "^7.0.0",
         "jpgraph/jpgraph": "^4.0",
-        "friendsofphp/php-cs-fixer": "@stable"
+        "friendsofphp/php-cs-fixer": "@stable",
+        "squizlabs/php_codesniffer": "^3.3"
     },
     "suggest": {
         "mpdf/mpdf": "Option for rendering PDF with PDF Writer",
diff --git a/composer.lock b/composer.lock
index ac3d4675..fe9fbc65 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1,10 +1,10 @@
 {
     "_readme": [
         "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "1aba55e3ac36d8d5015f9b3193f93c23",
+    "content-hash": "66067b3ab7afd673a28cf0b31eb9ae20",
     "packages": [
         {
             "name": "markbaker/complex",
@@ -2201,64 +2201,37 @@
         },
         {
             "name": "squizlabs/php_codesniffer",
-            "version": "2.8.1",
+            "version": "3.3.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/squizlabs/PHP_CodeSniffer.git",
-                "reference": "d7cf0d894e8aa4c73712ee4a331cc1eaa37cdc7d"
+                "reference": "628a481780561150481a9ec74709092b9759b3ec"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/squizlabs/PHP_CodeSniffer/zipball/d7cf0d894e8aa4c73712ee4a331cc1eaa37cdc7d",
-                "reference": "d7cf0d894e8aa4c73712ee4a331cc1eaa37cdc7d",
+                "url": "https://api.github.com/repos/squizlabs/PHP_CodeSniffer/zipball/628a481780561150481a9ec74709092b9759b3ec",
+                "reference": "628a481780561150481a9ec74709092b9759b3ec",
                 "shasum": ""
             },
             "require": {
                 "ext-simplexml": "*",
                 "ext-tokenizer": "*",
                 "ext-xmlwriter": "*",
-                "php": ">=5.1.2"
+                "php": ">=5.4.0"
             },
             "require-dev": {
-                "phpunit/phpunit": "~4.0"
+                "phpunit/phpunit": "^4.0 || ^5.0 || ^6.0 || ^7.0"
             },
             "bin": [
-                "scripts/phpcs",
-                "scripts/phpcbf"
+                "bin/phpcs",
+                "bin/phpcbf"
             ],
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "2.x-dev"
+                    "dev-master": "3.x-dev"
                 }
             },
-            "autoload": {
-                "classmap": [
-                    "CodeSniffer.php",
-                    "CodeSniffer/CLI.php",
-                    "CodeSniffer/Exception.php",
-                    "CodeSniffer/File.php",
-                    "CodeSniffer/Fixer.php",
-                    "CodeSniffer/Report.php",
-                    "CodeSniffer/Reporting.php",
-                    "CodeSniffer/Sniff.php",
-                    "CodeSniffer/Tokens.php",
-                    "CodeSniffer/Reports/",
-                    "CodeSniffer/Tokenizers/",
-                    "CodeSniffer/DocGenerators/",
-                    "CodeSniffer/Standards/AbstractPatternSniff.php",
-                    "CodeSniffer/Standards/AbstractScopeSniff.php",
-                    "CodeSniffer/Standards/AbstractVariableSniff.php",
-                    "CodeSniffer/Standards/IncorrectPatternException.php",
-                    "CodeSniffer/Standards/Generic/Sniffs/",
-                    "CodeSniffer/Standards/MySource/Sniffs/",
-                    "CodeSniffer/Standards/PEAR/Sniffs/",
-                    "CodeSniffer/Standards/PSR1/Sniffs/",
-                    "CodeSniffer/Standards/PSR2/Sniffs/",
-                    "CodeSniffer/Standards/Squiz/Sniffs/",
-                    "CodeSniffer/Standards/Zend/Sniffs/"
-                ]
-            },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
                 "BSD-3-Clause"
@@ -2275,7 +2248,7 @@
                 "phpcs",
                 "standards"
             ],
-            "time": "2017-03-01T22:17:45+00:00"
+            "time": "2018-07-26T23:47:18+00:00"
         },
         {
             "name": "symfony/console",
diff --git a/samples/Autofilter/10_Autofilter_selection_1.php b/samples/Autofilter/10_Autofilter_selection_1.php
index 4f1fc486..30efc194 100644
--- a/samples/Autofilter/10_Autofilter_selection_1.php
+++ b/samples/Autofilter/10_Autofilter_selection_1.php
@@ -125,7 +125,7 @@ $autoFilter->getColumn('C')
     )
     ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 // Filter the Date column on a filter value of the first day of every period of the current year
-//	We us a dateGroup ruletype for this, although it is still a standard filter
+// We us a dateGroup ruletype for this, although it is still a standard filter
 foreach ($periods as $period) {
     $endDate = date('t', mktime(0, 0, 0, $period, 1, $currentYear));
 
diff --git a/samples/Autofilter/10_Autofilter_selection_2.php b/samples/Autofilter/10_Autofilter_selection_2.php
index 63f11a22..1520c972 100644
--- a/samples/Autofilter/10_Autofilter_selection_2.php
+++ b/samples/Autofilter/10_Autofilter_selection_2.php
@@ -108,7 +108,7 @@ $spreadsheet->getActiveSheet()->setAutoFilter($spreadsheet->getActiveSheet()->ca
 $autoFilter = $spreadsheet->getActiveSheet()->getAutoFilter();
 $helper->log('Set active filters');
 // Filter the Country column on a filter value of Germany
-//	As it's just a simple value filter, we can use FILTERTYPE_FILTER
+// As it's just a simple value filter, we can use FILTERTYPE_FILTER
 $autoFilter->getColumn('C')
     ->setFilterType(Column::AUTOFILTER_FILTERTYPE_FILTER)
     ->createRule()
diff --git a/samples/Autofilter/10_Autofilter_selection_display.php b/samples/Autofilter/10_Autofilter_selection_display.php
index b2b77b74..50986bfa 100644
--- a/samples/Autofilter/10_Autofilter_selection_display.php
+++ b/samples/Autofilter/10_Autofilter_selection_display.php
@@ -125,7 +125,7 @@ $autoFilter->getColumn('C')
     )
     ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 // Filter the Date column on a filter value of the first day of every period of the current year
-//	We us a dateGroup ruletype for this, although it is still a standard filter
+// We us a dateGroup ruletype for this, although it is still a standard filter
 foreach ($periods as $period) {
     $endDate = date('t', mktime(0, 0, 0, $period, 1, $currentYear));
 
diff --git a/samples/Basic/08_Conditional_formatting.php b/samples/Basic/08_Conditional_formatting.php
index 0ad45c36..2f548632 100644
--- a/samples/Basic/08_Conditional_formatting.php
+++ b/samples/Basic/08_Conditional_formatting.php
@@ -84,7 +84,7 @@ $conditionalStyles[] = $conditional2;
 $conditionalStyles[] = $conditional3;
 $spreadsheet->getActiveSheet()->getStyle('B2')->setConditionalStyles($conditionalStyles);
 
-//	duplicate the conditional styles across a range of cells
+// duplicate the conditional styles across a range of cells
 $helper->log('Duplicate the conditional formatting across a range of cells');
 $spreadsheet->getActiveSheet()->duplicateConditionalStyle(
     $spreadsheet->getActiveSheet()->getStyle('B2')->getConditionalStyles(),
diff --git a/samples/Basic/08_Conditional_formatting_2.php b/samples/Basic/08_Conditional_formatting_2.php
index 607578cd..818cdd9f 100644
--- a/samples/Basic/08_Conditional_formatting_2.php
+++ b/samples/Basic/08_Conditional_formatting_2.php
@@ -59,7 +59,7 @@ $conditionalStyles[] = $conditional1;
 $conditionalStyles[] = $conditional3;
 $spreadsheet->getActiveSheet()->getStyle('A1')->setConditionalStyles($conditionalStyles);
 
-//	duplicate the conditional styles across a range of cells
+// duplicate the conditional styles across a range of cells
 $helper->log('Duplicate the conditional formatting across a range of cells');
 $spreadsheet->getActiveSheet()->duplicateConditionalStyle(
     $spreadsheet->getActiveSheet()->getStyle('A1')->getConditionalStyles(),
diff --git a/samples/Chart/32_Chart_read_write_HTML.php b/samples/Chart/32_Chart_read_write_HTML.php
index 8071edd2..5febbf93 100644
--- a/samples/Chart/32_Chart_read_write_HTML.php
+++ b/samples/Chart/32_Chart_read_write_HTML.php
@@ -5,7 +5,7 @@ use PhpOffice\PhpSpreadsheet\Settings;
 
 require __DIR__ . '/../Header.php';
 
-//	Change these values to select the Rendering library that you wish to use
+// Change these values to select the Rendering library that you wish to use
 Settings::setChartRenderer(\PhpOffice\PhpSpreadsheet\Chart\Renderer\JpGraph::class);
 
 $inputFileType = 'Xlsx';
diff --git a/samples/Chart/32_Chart_read_write_PDF.php b/samples/Chart/32_Chart_read_write_PDF.php
index 7cc51565..ee3ad0e0 100644
--- a/samples/Chart/32_Chart_read_write_PDF.php
+++ b/samples/Chart/32_Chart_read_write_PDF.php
@@ -7,7 +7,7 @@ require __DIR__ . '/../Header.php';
 
 IOFactory::registerWriter('Pdf', \PhpOffice\PhpSpreadsheet\Writer\Pdf\Mpdf::class);
 
-//	Change these values to select the Rendering library that you wish to use
+// Change these values to select the Rendering library that you wish to use
 Settings::setChartRenderer(\PhpOffice\PhpSpreadsheet\Chart\Renderer\JpGraph::class);
 
 $inputFileType = 'Xlsx';
diff --git a/samples/Chart/33_Chart_create_area.php b/samples/Chart/33_Chart_create_area.php
index f44232fb..4478d2dd 100644
--- a/samples/Chart/33_Chart_create_area.php
+++ b/samples/Chart/33_Chart_create_area.php
@@ -23,42 +23,42 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_AREACHART, // plotType
     DataSeries::GROUPING_PERCENT_STACKED, // plotGrouping
@@ -68,15 +68,15 @@ $series = new DataSeries(
     $dataSeriesValues          // plotValues
 );
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
 $title = new Title('Test %age-Stacked Area Chart');
 $yAxisLabel = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -88,11 +88,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('A7');
 $chart->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_bar_stacked.php b/samples/Chart/33_Chart_create_bar_stacked.php
index 16654a15..7ba4d8de 100644
--- a/samples/Chart/33_Chart_create_bar_stacked.php
+++ b/samples/Chart/33_Chart_create_bar_stacked.php
@@ -23,42 +23,42 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_BARCHART, // plotType
     DataSeries::GROUPING_STACKED, // plotGrouping
@@ -67,19 +67,19 @@ $series = new DataSeries(
     $xAxisTickValues, // plotCategory
     $dataSeriesValues        // plotValues
 );
-//	Set additional dataseries parameters
-//		Make it a horizontal bar rather than a vertical column graph
+// Set additional dataseries parameters
+//     Make it a horizontal bar rather than a vertical column graph
 $series->setPlotDirection(DataSeries::DIRECTION_BAR);
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title = new Title('Test Chart');
 $yAxisLabel = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -91,11 +91,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('A7');
 $chart->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_column.php b/samples/Chart/33_Chart_create_column.php
index bc676447..9ffe9d3f 100644
--- a/samples/Chart/33_Chart_create_column.php
+++ b/samples/Chart/33_Chart_create_column.php
@@ -23,42 +23,42 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_BARCHART, // plotType
     DataSeries::GROUPING_STANDARD, // plotGrouping
@@ -67,19 +67,19 @@ $series = new DataSeries(
     $xAxisTickValues, // plotCategory
     $dataSeriesValues        // plotValues
 );
-//	Set additional dataseries parameters
-//		Make it a vertical column rather than a horizontal bar graph
+// Set additional dataseries parameters
+//     Make it a vertical column rather than a horizontal bar graph
 $series->setPlotDirection(DataSeries::DIRECTION_COL);
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title = new Title('Test Column Chart');
 $yAxisLabel = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -91,11 +91,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('A7');
 $chart->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_column_2.php b/samples/Chart/33_Chart_create_column_2.php
index a00b23b8..bba9210a 100644
--- a/samples/Chart/33_Chart_create_column_2.php
+++ b/samples/Chart/33_Chart_create_column_2.php
@@ -31,42 +31,42 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	'Budget'
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	'Forecast'
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$E$1', null, 1), //	'Actual'
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 'Budget'
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 'Forecast'
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$E$1', null, 1), // 'Actual'
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$B$13', null, 12), //	Q1 to Q4 for 2010 to 2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$B$13', null, 12), // Q1 to Q4 for 2010 to 2012
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$13', null, 12),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$13', null, 12),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$E$2:$E$13', null, 12),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_BARCHART, // plotType
     DataSeries::GROUPING_CLUSTERED, // plotGrouping
@@ -75,20 +75,20 @@ $series = new DataSeries(
     $xAxisTickValues, // plotCategory
     $dataSeriesValues        // plotValues
 );
-//	Set additional dataseries parameters
-//		Make it a vertical column rather than a horizontal bar graph
+// Set additional dataseries parameters
+//     Make it a vertical column rather than a horizontal bar graph
 $series->setPlotDirection(DataSeries::DIRECTION_COL);
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_BOTTOM, null, false);
 
 $title = new Title('Test Grouped Column Chart');
 $xAxisLabel = new Title('Financial Period');
 $yAxisLabel = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -100,11 +100,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('G2');
 $chart->setBottomRightPosition('P20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_composite.php b/samples/Chart/33_Chart_create_composite.php
index 272048d2..83dc34a9 100644
--- a/samples/Chart/33_Chart_create_composite.php
+++ b/samples/Chart/33_Chart_create_composite.php
@@ -31,46 +31,46 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels1 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	Temperature
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // Temperature
 ];
 $dataSeriesLabels2 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	Rainfall
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // Rainfall
 ];
 $dataSeriesLabels3 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	Humidity
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // Humidity
 ];
 
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$13', null, 12), // Jan to Dec
 ];
 
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues1 = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$13', null, 12),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series1 = new DataSeries(
     DataSeries::TYPE_BARCHART, // plotType
     DataSeries::GROUPING_CLUSTERED, // plotGrouping
@@ -79,22 +79,22 @@ $series1 = new DataSeries(
     $xAxisTickValues, // plotCategory
     $dataSeriesValues1        // plotValues
 );
-//	Set additional dataseries parameters
-//		Make it a vertical column rather than a horizontal bar graph
+// Set additional dataseries parameters
+//     Make it a vertical column rather than a horizontal bar graph
 $series1->setPlotDirection(DataSeries::DIRECTION_COL);
 
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues2 = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$13', null, 12),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series2 = new DataSeries(
     DataSeries::TYPE_LINECHART, // plotType
     DataSeries::GROUPING_STANDARD, // plotGrouping
@@ -104,18 +104,18 @@ $series2 = new DataSeries(
     $dataSeriesValues2        // plotValues
 );
 
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues3 = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$13', null, 12),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series3 = new DataSeries(
     DataSeries::TYPE_AREACHART, // plotType
     DataSeries::GROUPING_STANDARD, // plotGrouping
@@ -125,14 +125,14 @@ $series3 = new DataSeries(
     $dataSeriesValues3        // plotValues
 );
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series1, $series2, $series3]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title = new Title('Average Weather Chart for Crete');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -144,11 +144,11 @@ $chart = new Chart(
     null   // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('F2');
 $chart->setBottomRightPosition('O16');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_line.php b/samples/Chart/33_Chart_create_line.php
index 3961d70c..bdaf0111 100644
--- a/samples/Chart/33_Chart_create_line.php
+++ b/samples/Chart/33_Chart_create_line.php
@@ -23,35 +23,35 @@ $worksheet->fromArray(
     ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
@@ -59,7 +59,7 @@ $dataSeriesValues = [
 ];
 $dataSeriesValues[2]->setLineWidth(60000);
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_LINECHART, // plotType
     DataSeries::GROUPING_STACKED, // plotGrouping
@@ -69,15 +69,15 @@ $series = new DataSeries(
     $dataSeriesValues        // plotValues
 );
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
 $title = new Title('Test Stacked Line Chart');
 $yAxisLabel = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -89,11 +89,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('A7');
 $chart->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_multiple_charts.php b/samples/Chart/33_Chart_create_multiple_charts.php
index b907a39a..10a11e13 100644
--- a/samples/Chart/33_Chart_create_multiple_charts.php
+++ b/samples/Chart/33_Chart_create_multiple_charts.php
@@ -23,42 +23,42 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels1 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues1 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues1 = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series1 = new DataSeries(
     DataSeries::TYPE_AREACHART, // plotType
     DataSeries::GROUPING_PERCENT_STACKED, // plotGrouping
@@ -68,15 +68,15 @@ $series1 = new DataSeries(
     $dataSeriesValues1          // plotValues
 );
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea1 = new PlotArea(null, [$series1]);
-//	Set the chart legend
+// Set the chart legend
 $legend1 = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
 $title1 = new Title('Test %age-Stacked Area Chart');
 $yAxisLabel1 = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart1 = new Chart(
     'chart1', // name
     $title1, // title
@@ -88,49 +88,49 @@ $chart1 = new Chart(
     $yAxisLabel1 // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart1->setTopLeftPosition('A7');
 $chart1->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart1);
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels2 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues2 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues2 = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series2 = new DataSeries(
     DataSeries::TYPE_BARCHART, // plotType
     DataSeries::GROUPING_STANDARD, // plotGrouping
@@ -139,19 +139,19 @@ $series2 = new DataSeries(
     $xAxisTickValues2, // plotCategory
     $dataSeriesValues2        // plotValues
 );
-//	Set additional dataseries parameters
-//		Make it a vertical column rather than a horizontal bar graph
+// Set additional dataseries parameters
+//     Make it a vertical column rather than a horizontal bar graph
 $series2->setPlotDirection(DataSeries::DIRECTION_COL);
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea2 = new PlotArea(null, [$series2]);
-//	Set the chart legend
+// Set the chart legend
 $legend2 = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title2 = new Title('Test Column Chart');
 $yAxisLabel2 = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart2 = new Chart(
     'chart2', // name
     $title2, // title
@@ -163,11 +163,11 @@ $chart2 = new Chart(
     $yAxisLabel2 // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart2->setTopLeftPosition('I7');
 $chart2->setBottomRightPosition('P20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart2);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_pie.php b/samples/Chart/33_Chart_create_pie.php
index 49726442..d4ec0752 100644
--- a/samples/Chart/33_Chart_create_pie.php
+++ b/samples/Chart/33_Chart_create_pie.php
@@ -24,38 +24,38 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels1 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues1 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues1 = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series1 = new DataSeries(
     DataSeries::TYPE_PIECHART, // plotType
     null, // plotGrouping (Pie charts don't have any grouping)
@@ -65,19 +65,19 @@ $series1 = new DataSeries(
     $dataSeriesValues1          // plotValues
 );
 
-//	Set up a layout object for the Pie chart
+// Set up a layout object for the Pie chart
 $layout1 = new Layout();
 $layout1->setShowVal(true);
 $layout1->setShowPercent(true);
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea1 = new PlotArea($layout1, [$series1]);
-//	Set the chart legend
+// Set the chart legend
 $legend1 = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title1 = new Title('Test Pie Chart');
 
-//	Create the chart
+// Create the chart
 $chart1 = new Chart(
     'chart1', // name
     $title1, // title
@@ -86,48 +86,48 @@ $chart1 = new Chart(
     true, // plotVisibleOnly
     0, // displayBlanksAs
     null, // xAxisLabel
-    null   // yAxisLabel		- Pie charts don't have a Y-Axis
+    null   // yAxisLabel - Pie charts don't have a Y-Axis
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart1->setTopLeftPosition('A7');
 $chart1->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart1);
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels2 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues2 = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues2 = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series2 = new DataSeries(
     DataSeries::TYPE_DONUTCHART, // plotType
     null, // plotGrouping (Donut charts don't have any grouping)
@@ -137,17 +137,17 @@ $series2 = new DataSeries(
     $dataSeriesValues2        // plotValues
 );
 
-//	Set up a layout object for the Pie chart
+// Set up a layout object for the Pie chart
 $layout2 = new Layout();
 $layout2->setShowVal(true);
 $layout2->setShowCatName(true);
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea2 = new PlotArea($layout2, [$series2]);
 
 $title2 = new Title('Test Donut Chart');
 
-//	Create the chart
+// Create the chart
 $chart2 = new Chart(
     'chart2', // name
     $title2, // title
@@ -156,14 +156,14 @@ $chart2 = new Chart(
     true, // plotVisibleOnly
     0, // displayBlanksAs
     null, // xAxisLabel
-    null   // yAxisLabel		- Like Pie charts, Donut charts don't have a Y-Axis
+    null   // yAxisLabel - Like Pie charts, Donut charts don't have a Y-Axis
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart2->setTopLeftPosition('I7');
 $chart2->setBottomRightPosition('P20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart2);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_radar.php b/samples/Chart/33_Chart_create_radar.php
index 9d05f858..e57914ab 100644
--- a/samples/Chart/33_Chart_create_radar.php
+++ b/samples/Chart/33_Chart_create_radar.php
@@ -32,41 +32,41 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$13', null, 12), // Jan to Dec
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$13', null, 12), // Jan to Dec
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$13', null, 12),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$13', null, 12),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_RADARCHART, // plotType
     null, // plotGrouping (Radar charts don't have any grouping)
@@ -79,17 +79,17 @@ $series = new DataSeries(
     DataSeries::STYLE_MARKER  // plotStyle
 );
 
-//	Set up a layout object for the Pie chart
+// Set up a layout object for the Pie chart
 $layout = new Layout();
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea($layout, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title = new Title('Test Radar Chart');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -98,14 +98,14 @@ $chart = new Chart(
     true, // plotVisibleOnly
     0, // displayBlanksAs
     null, // xAxisLabel
-    null   // yAxisLabel		- Radar charts don't have a Y-Axis
+    null   // yAxisLabel - Radar charts don't have a Y-Axis
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('F2');
 $chart->setBottomRightPosition('M15');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_scatter.php b/samples/Chart/33_Chart_create_scatter.php
index 2070fe26..12fc2bdc 100644
--- a/samples/Chart/33_Chart_create_scatter.php
+++ b/samples/Chart/33_Chart_create_scatter.php
@@ -23,36 +23,36 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
+// Set the X-Axis Labels
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_SCATTERCHART, // plotType
     null, // plotGrouping (Scatter charts don't have any grouping)
@@ -65,15 +65,15 @@ $series = new DataSeries(
     DataSeries::STYLE_LINEMARKER  // plotStyle
 );
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
 $title = new Title('Test Scatter Chart');
 $yAxisLabel = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -85,11 +85,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('A7');
 $chart->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Chart/33_Chart_create_stock.php b/samples/Chart/33_Chart_create_stock.php
index 2342d1a4..7a9f7274 100644
--- a/samples/Chart/33_Chart_create_stock.php
+++ b/samples/Chart/33_Chart_create_stock.php
@@ -29,36 +29,36 @@ $worksheet->fromArray(
 );
 $worksheet->getStyle('B2:E6')->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_NUMBER_00);
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //Max / Open
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //Min / Close
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //Min Threshold / Min
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$E$1', null, 1), //Max Threshold / Max
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$6', null, 5), //	Counts
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$6', null, 5), // Counts
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$6', null, 5),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$6', null, 5),
@@ -66,7 +66,7 @@ $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$E$2:$E$6', null, 5),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_STOCKCHART, // plotType
     null, // plotGrouping - if we set this to not null, then xlsx throws error
@@ -76,16 +76,16 @@ $series = new DataSeries(
     $dataSeriesValues       // plotValues
 );
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title = new Title('Test Stock Chart');
 $xAxisLabel = new Title('Counts');
 $yAxisLabel = new Title('Values');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'stock-chart', // name
     $title, // title
@@ -97,11 +97,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('A7');
 $chart->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 // Save Excel 2007 file
diff --git a/samples/Reader/11_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_1).php b/samples/Reader/11_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_1).php
index 892ab338..18562217 100644
--- a/samples/Reader/11_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_1).php
+++ b/samples/Reader/11_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_1).php
@@ -57,7 +57,7 @@ for ($startRow = 2; $startRow <= 240; $startRow += $chunkSize) {
     // Load only the rows that match our filter from $inputFileName to a PhpSpreadsheet Object
     $spreadsheet = $reader->load($inputFileName);
 
-    //	Do some processing here
+    // Do some processing here
 
     $sheetData = $spreadsheet->getActiveSheet()->toArray(null, true, true, true);
     var_dump($sheetData);
diff --git a/samples/Reader/12_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_2).php b/samples/Reader/12_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_2).php
index 0a3e8f3c..1f39ec4d 100644
--- a/samples/Reader/12_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_2).php
+++ b/samples/Reader/12_Reading_a_workbook_in_chunks_using_a_configurable_read_filter_(version_2).php
@@ -60,7 +60,7 @@ for ($startRow = 2; $startRow <= 240; $startRow += $chunkSize) {
     // Load only the rows that match our filter from $inputFileName to a PhpSpreadsheet Object
     $spreadsheet = $reader->load($inputFileName);
 
-    //	Do some processing here
+    // Do some processing here
 
     $sheetData = $spreadsheet->getActiveSheet()->toArray(null, true, true, true);
     var_dump($sheetData);
diff --git a/samples/Reading_workbook_data/Custom_properties.php b/samples/Reading_workbook_data/Custom_properties.php
index 3c40440b..1c222b50 100644
--- a/samples/Reading_workbook_data/Custom_properties.php
+++ b/samples/Reading_workbook_data/Custom_properties.php
@@ -25,24 +25,24 @@ foreach ($customPropertyList as $customPropertyName) {
 
     // Manipulate properties as appropriate for display purposes
     switch ($propertyType) {
-        case 'i':    //	integer
+        case 'i':    // integer
             $propertyType = 'integer number';
 
             break;
-        case 'f':    //	float
+        case 'f':    // float
             $propertyType = 'floating point number';
 
             break;
-        case 's':    //	string
+        case 's':    // string
             $propertyType = 'string';
 
             break;
-        case 'd':    //	date
+        case 'd':    // date
             $propertyValue = date('l, d<\s\up>S</\s\up> F Y g:i A', $propertyValue);
             $propertyType = 'date';
 
             break;
-        case 'b':    //	boolean
+        case 'b':    // boolean
             $propertyValue = ($propertyValue) ? 'TRUE' : 'FALSE';
             $propertyType = 'boolean';
 
diff --git a/samples/templates/chartSpreadsheet.php b/samples/templates/chartSpreadsheet.php
index a63f316b..84c8c956 100644
--- a/samples/templates/chartSpreadsheet.php
+++ b/samples/templates/chartSpreadsheet.php
@@ -20,42 +20,42 @@ $worksheet->fromArray(
         ]
 );
 
-//	Set the Labels for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Labels for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesLabels = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), //	2010
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), //	2011
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$B$1', null, 1), // 2010
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$C$1', null, 1), // 2011
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$D$1', null, 1), // 2012
 ];
-//	Set the X-Axis Labels
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the X-Axis Labels
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $xAxisTickValues = [
-    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$2:$A$5', null, 4), // Q1 to Q4
 ];
-//	Set the Data values for each data series we want to plot
-//		Datatype
-//		Cell reference for data
-//		Format Code
-//		Number of datapoints in series
-//		Data values
-//		Data Marker
+// Set the Data values for each data series we want to plot
+//     Datatype
+//     Cell reference for data
+//     Format Code
+//     Number of datapoints in series
+//     Data values
+//     Data Marker
 $dataSeriesValues = [
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$B$2:$B$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$C$2:$C$5', null, 4),
     new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
-//	Build the dataseries
+// Build the dataseries
 $series = new DataSeries(
     DataSeries::TYPE_BARCHART, // plotType
     DataSeries::GROUPING_CLUSTERED, // plotGrouping
@@ -64,19 +64,19 @@ $series = new DataSeries(
     $xAxisTickValues, // plotCategory
     $dataSeriesValues        // plotValues
 );
-//	Set additional dataseries parameters
-//		Make it a horizontal bar rather than a vertical column graph
+// Set additional dataseries parameters
+//     Make it a horizontal bar rather than a vertical column graph
 $series->setPlotDirection(DataSeries::DIRECTION_BAR);
 
-//	Set the series in the plot area
+// Set the series in the plot area
 $plotArea = new PlotArea(null, [$series]);
-//	Set the chart legend
+// Set the chart legend
 $legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
 $title = new Title('Test Bar Chart');
 $yAxisLabel = new Title('Value ($k)');
 
-//	Create the chart
+// Create the chart
 $chart = new Chart(
     'chart1', // name
     $title, // title
@@ -88,11 +88,11 @@ $chart = new Chart(
     $yAxisLabel  // yAxisLabel
 );
 
-//	Set the position where the chart should appear in the worksheet
+// Set the position where the chart should appear in the worksheet
 $chart->setTopLeftPosition('A7');
 $chart->setBottomRightPosition('H20');
 
-//	Add the chart to the worksheet
+// Add the chart to the worksheet
 $worksheet->addChart($chart);
 
 return $spreadsheet;