Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php
private static function checkSheetTitle($pValue)
    {
        // Some of the printable ASCII characters are invalid:  * : / \ ? [ ]
        if (str_replace(self::$invalidCharacters, '', $pValue) !== $pValue) {
            throw new Exception('Invalid character found in sheet title');
        }

        // Maximum 31 characters allowed for sheet title
        if (Shared\StringHelper::countCharacters($pValue) > 31) {
            throw new Exception('Maximum 31 characters allowed in sheet title.');
        }

        return $pValue;
    }
private static function checkSheetTitle($pValue)
    {
        // Some of the printable ASCII characters are invalid:  * : / \ ? [ ]
        if (str_replace(self::$invalidCharacters, '', $pValue) !== $pValue) {
            throw new Exception('Invalid character found in sheet title');
        }

        // Maximum 31 characters allowed for sheet title
        if (Shared\StringHelper::countCharacters($pValue) > 31) {
            throw new Exception('Maximum 31 characters allowed in sheet title.');
        }

        return $pValue;
    }
Check sheet title for valid Excel syntax.

@param string $pValue The string to check

@throws Exception

@return string The valid string