Apply small code style improvements

CHANGELOG.md

@@ -33,6 +33,7 @@ and this project adheres to [Semantic Versioning](https://semver.org). Thia is a
 - Unexpected Exception in Php DateTime. [Issue #4696](https://github.com/PHPOffice/PhpSpreadsheet/issues/4696) [Issue #917](https://github.com/PHPOffice/PhpSpreadsheet/issues/917) [PR #4697](https://github.com/PHPOffice/PhpSpreadsheet/pull/4697)
 - Add missing Dutch translation to translation file. [PR #4707](https://github.com/PHPOffice/PhpSpreadsheet/pull/4707)
 - Fix lots of typos throughout codebase. [PR #4705](https://github.com/PHPOffice/PhpSpreadsheet/pull/4705)
+- Apply small code style improvements. [PR #4708](https://github.com/PHPOffice/PhpSpreadsheet/pull/4708)
 - Implement missing `INFO` function. [PR #4709](https://github.com/PHPOffice/PhpSpreadsheet/pull/4709)
 
 ## 2025-10-25 - 5.2.0

src/PhpSpreadsheet/Calculation/FormulaParser.php

@@ -463,16 +463,8 @@ private function parseToTokens(): void
         $tokenCount = count($tokens1);
         for ($i = 0; $i < $tokenCount; ++$i) {
             $token = $tokens1[$i];
-            if (isset($tokens1[$i - 1])) {
-                $previousToken = $tokens1[$i - 1];
-            } else {
-                $previousToken = null;
-            }
-            if (isset($tokens1[$i + 1])) {
-                $nextToken = $tokens1[$i + 1];
-            } else {
-                $nextToken = null;
-            }
+            $previousToken = $tokens1[$i - 1] ?? null;
+            $nextToken = $tokens1[$i + 1] ?? null;
 
             if ($token->getTokenType() != FormulaToken::TOKEN_TYPE_WHITESPACE) {
                 $tokens2[] = $token;
@@ -518,11 +510,7 @@ private function parseToTokens(): void
         $tokenCount = count($tokens2);
         for ($i = 0; $i < $tokenCount; ++$i) {
             $token = $tokens2[$i];
-            if (isset($tokens2[$i - 1])) {
-                $previousToken = $tokens2[$i - 1];
-            } else {
-                $previousToken = null;
-            }
+            $previousToken = $tokens2[$i - 1] ?? null;
 
             if ($token->getTokenType() == FormulaToken::TOKEN_TYPE_OPERATORINFIX && $token->getValue() == '-') {
                 if ($i == 0) {

src/PhpSpreadsheet/Calculation/Information/Value.php

@@ -265,7 +265,7 @@ public static function asNumber($value = null)
         if (is_bool($value)) {
             return (int) $value;
         }
-        if (is_string($value) && substr($value, 0, 1) === '#') {
+        if (is_string($value) && str_starts_with($value, '#')) {
             return $value;
         }
 

src/PhpSpreadsheet/Calculation/LookupRef/Indirect.php

@@ -106,7 +106,7 @@ public static function INDIRECT($cellAddress, mixed $a1fmt, Cell $cell): string|
      */
     private static function extractRequiredCells(?Worksheet $worksheet, string $cellAddress): array
     {
-        return Calculation::getInstance($worksheet !== null ? $worksheet->getParent() : null)
+        return Calculation::getInstance($worksheet?->getParent())
             ->extractCellRange($cellAddress, $worksheet, false, createCell: true);
     }
 

src/PhpSpreadsheet/Calculation/LookupRef/Offset.php

@@ -102,7 +102,7 @@ public static function OFFSET(?string $cellAddress = null, $rows = 0, $columns =
     /** @return mixed[] */
     private static function extractRequiredCells(?Worksheet $worksheet, string $cellAddress): array
     {
-        return Calculation::getInstance($worksheet !== null ? $worksheet->getParent() : null)
+        return Calculation::getInstance($worksheet?->getParent())
             ->extractCellRange($cellAddress, $worksheet, false);
     }
 

src/PhpSpreadsheet/Cell/Coordinate.php

@@ -316,7 +316,7 @@ private static function validateReferenceAndGetData($reference): array
 
         $worksheet = $matches['worksheet'];
         if ($worksheet !== '') {
-            if (substr($worksheet, 0, 1) === "'" && substr($worksheet, -1, 1) === "'") {
+            if (str_starts_with($worksheet, "'") && str_ends_with($worksheet, "'")) {
                 $worksheet = substr($worksheet, 1, -1);
             }
             $data['worksheet'] = strtolower($worksheet);

src/PhpSpreadsheet/Collection/Cells.php

@@ -281,7 +281,7 @@ public function getHighestColumn($row = null): string
                 continue;
             }
             $column = ($coordinate % self::MAX_COLUMN_ID) ?: self::MAX_COLUMN_ID;
-            $maxColumn = $maxColumn > $column ? $maxColumn : $column;
+            $maxColumn = max($column, $maxColumn);
         }
 
         return Coordinate::stringFromColumnIndex($maxColumn);

src/PhpSpreadsheet/Reader/Html.php

@@ -1129,7 +1129,7 @@ private function insertImage(Worksheet $sheet, string $column, int $row, array $
         $styleArray = self::getStyleArray($attributes);
 
         $src = $attributes['src'];
-        if (substr($src, 0, 5) !== 'data:') {
+        if (!str_starts_with($src, 'data:')) {
             $src = urldecode($src);
         }
         $width = isset($attributes['width']) ? (float) $attributes['width'] : ($styleArray['width'] ?? null);
@@ -1195,13 +1195,13 @@ private static function getStyleArray(array $attributes): array
                     $arrayKey = trim($value[0]);
                     $arrayValue = trim($value[1]);
                     if ($arrayKey === 'width') {
-                        if (substr($arrayValue, -2) === 'px') {
+                        if (str_ends_with($arrayValue, 'px')) {
                             $arrayValue = (string) (((float) substr($arrayValue, 0, -2)));
                         } else {
                             $arrayValue = (new CssDimension($arrayValue))->toUnit(CssDimension::UOM_PIXELS);
                         }
                     } elseif ($arrayKey === 'height') {
-                        if (substr($arrayValue, -2) === 'px') {
+                        if (str_ends_with($arrayValue, 'px')) {
                             $arrayValue = substr($arrayValue, 0, -2);
                         } else {
                             $arrayValue = (new CssDimension($arrayValue))->toUnit(CssDimension::UOM_PIXELS);

src/PhpSpreadsheet/Reader/Security/XmlScanner.php

@@ -64,7 +64,7 @@ private function toUtf8(string $xml): string
 
     private function findCharSet(string $xml): string
     {
-        if (substr($xml, 0, 4) === "\x4c\x6f\xa7\x94") {
+        if (str_starts_with($xml, "\x4c\x6f\xa7\x94")) {
             throw new Reader\Exception('EBCDIC encoding not permitted');
         }
         $encoding = Reader\Csv::guessEncodingBom('', $xml);

src/PhpSpreadsheet/Reader/Xlsx.php

@@ -2430,7 +2430,7 @@ private function readBackgroundImage(
                 $attrs = $rel->attributes() ?? [];
                 $rid = (string) ($attrs['Id'] ?? '');
                 $target = (string) ($attrs['Target'] ?? '');
-                if ($rid === $id && substr($target, 0, 2) === '..') {
+                if ($rid === $id && str_starts_with($target, '..')) {
                     $target = 'xl' . substr($target, 2);
                     $content = $this->getFromZipArchive($this->zip, $target);
                     $docSheet->setBackgroundImage($content);

src/PhpSpreadsheet/Style/NumberFormat/PercentageFormatter.php

@@ -32,7 +32,7 @@ public static function format($value, string $format): string
         }
         // Number of digits to display before the decimal
         if (preg_match('/([#0,]+)\.?/u', $format, $matches)) {
-            $firstZero = preg_replace('/^[#,]*/', '', $matches[1]) ?? '';
+            $firstZero = ltrim($matches[1], '#,');
             $wholePartSize = max($wholePartSize, strlen($firstZero));
         }
 

src/PhpSpreadsheet/Worksheet/Worksheet.php

@@ -3411,7 +3411,7 @@ public static function extractSheetTitle(?string $range, bool $returnRange = fal
     public static function unApostrophizeTitle(?string $title): string
     {
         $title ??= '';
-        if ($title[0] === "'" && substr($title, -1) === "'") {
+        if (str_starts_with($title, "'") && str_ends_with($title, "'")) {
             $title = str_replace("''", "'", substr($title, 1, -1));
         }
 

src/PhpSpreadsheet/Writer/Xls/Workbook.php

@@ -551,7 +551,7 @@ private function parseDefinedNameValue(DefinedName $definedName): string
             if (empty($worksheet)) {
                 if (($offset === 0) || ($definedRange[$offset - 1] !== ':')) {
                     // We should have a worksheet
-                    $worksheet = $definedName->getWorksheet() ? $definedName->getWorksheet()->getTitle() : null;
+                    $worksheet = $definedName->getWorksheet()?->getTitle();
                 }
             } else {
                 $worksheet = str_replace("''", "'", trim($worksheet, "'"));