Add method getHighestColumnName

README.md

@@ -84,6 +84,8 @@ try {
 	$row = $row->getNextRow();
 	$row = $xlsxFastEditor->getLastRow($worksheetId1);
 
+	$xlsxFastEditor->getHighestColumnName($worksheetId1);
+
 	// Methods for rows
 	$rowNumber = $row->number();
 	$cell = $row->getCellOrNull('D2');

src/XlsxFastEditor.php

@@ -565,6 +565,32 @@ public static function cellOrderCompare(string $ref1, string $ref2): int
 		return strcmp($ref1, $ref2);
 	}
 
+	/**
+	 * Gives the name of the highest column used in the spreadsheet (e.g. `BA`),
+	 * or null if there is none.
+	 * @throws XlsxFastEditorFileFormatException
+	 * @throws XlsxFastEditorXmlException
+	 */
+	public function getHighestColumnName(int $sheetNumber): ?string
+	{
+		$rightMostCell = '';
+		$xpath = $this->getXPathFromPath(self::getWorksheetPath($sheetNumber));
+		$cs = $xpath->query("/o:worksheet/o:sheetData/o:row/o:c[last()]");
+		if ($cs !== false) {
+			for ($i = 0; $i < $cs->length; $i++) {
+				$c = $cs[$i];
+				if (!($c instanceof \DOMElement)) {
+					throw new XlsxFastEditorXmlException("Error querying XML fragment for row {$sheetNumber}!");
+				}
+				$cellName = $c->getAttribute('r');
+				if ($cellName !== '' && ($rightMostCell === '' || self::cellOrderCompare($rightMostCell, $cellName) < 0)) {
+					$rightMostCell = $cellName;
+				}
+			}
+		}
+		return $rightMostCell === '' ? null : XlsxFastEditorCell::nameToColumn($rightMostCell);
+	}
+
 	/** To return `null` when accessing a row or cell that does not exist, e.g. via {@see XlsxFastEditor::getCell()} */
 	public const ACCESS_MODE_NULL = 0;
 	/** To throw an exception when accessing a row or cell that does not exist, e.g. via {@see XlsxFastEditor::getCell()} */

src/XlsxFastEditorCell.php

@@ -49,17 +49,26 @@ public function name(): string
 	}
 
 	/**
-	 * Column name (e.g., `'D'`).
+	 * $return column name (e.g., `'D'`).
 	 * @throws XlsxFastEditorXmlException
 	 */
-	public function column(): string
+	public static function nameToColumn(string $name): string
 	{
-		if (preg_match('/^([A-Z]+)/', $this->name(), $matches) == 0 || empty($matches[1])) {
-			throw new XlsxFastEditorXmlException("Error querying column name for cell {$this->name()}!");
+		if (preg_match('/^([A-Z]+)/', $name, $matches) == 0 || empty($matches[1])) {
+			throw new XlsxFastEditorXmlException("Error querying column name for cell name {$name}!");
 		}
 		return $matches[1];
 	}
 
+	/**
+	 * Column name (e.g., `'D'`).
+	 * @throws XlsxFastEditorXmlException
+	 */
+	public function column(): string
+	{
+		return self::nameToColumn($this->name());
+	}
+
 	/**
 	 * Access the previous existing cell, if any, `null` otherwise.
 	 * ℹ️ This is a faster method than `XlsxFastEditorRow::getCellOrNull()`

tests/test.php

@@ -15,7 +15,7 @@
 try {
 	$xlsxFastEditor = new XlsxFastEditor(__DIR__ . '/_copy.xlsx');
 
-	assert($xlsxFastEditor->getWorksheetCount() === 2);
+	assert($xlsxFastEditor->getWorksheetCount() === 3);
 
 	date_default_timezone_set('UTC');
 	assert($xlsxFastEditor->getWorkbookDateSystem() === 1900);
@@ -63,6 +63,10 @@
 	assert($xlsxFastEditor->getRow($sheet1, 3)?->getLastCell()?->name() === 'F3');
 	assert($xlsxFastEditor->getLastRow($sheet1)?->number() === 4);
 
+	$sheet3 = $xlsxFastEditor->getWorksheetNumber('Sheet3');
+	assert($sheet3 === 3);
+	assert($xlsxFastEditor->getHighestColumnName($sheet3) === 'G');
+
 	$row4 = $xlsxFastEditor->getRow($sheet1, 4);
 	assert($row4 !== null);
 	assert($row4->getPreviousRow()?->getNextRow()?->number() === 4);