# tablepress/3.4/libraries/vendor/PhpSpreadsheet/Shared/StringHelper.php

TablePress – Tables in WordPress made easy, version 3.4. 885 lines.

- Page: https://pluginprobe.com/plugins/tablepress/3.4/code/libraries/vendor/PhpSpreadsheet/Shared/StringHelper.php
- Raw: https://pluginprobe.com/plugins/tablepress/3.4/raw/libraries/vendor/PhpSpreadsheet/Shared/StringHelper.php
- Modified: 2026-09-30T03:50:46+00:00

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```php
<?php

namespace TablePress\PhpOffice\PhpSpreadsheet\Shared;

use TablePress\Composer\Pcre\Preg;
use IntlCalendar;
use NumberFormatter;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Calculation;
use TablePress\PhpOffice\PhpSpreadsheet\Exception as SpreadsheetException;
use Stringable;

class StringHelper
{
	private const CONTROL_CHARACTERS_KEYS = [
		"\x00",
		"\x01",
		"\x02",
		"\x03",
		"\x04",
		"\x05",
		"\x06",
		"\x07",
		"\x08",
		"\x0b",
		"\x0c",
		"\x0e",
		"\x0f",
		"\x10",
		"\x11",
		"\x12",
		"\x13",
		"\x14",
		"\x15",
		"\x16",
		"\x17",
		"\x18",
		"\x19",
		"\x1a",
		"\x1b",
		"\x1c",
		"\x1d",
		"\x1e",
		"\x1f",
	];
	private const CONTROL_CHARACTERS_VALUES = [
		'_x0000_',
		'_x0001_',
		'_x0002_',
		'_x0003_',
		'_x0004_',
		'_x0005_',
		'_x0006_',
		'_x0007_',
		'_x0008_',
		'_x000B_',
		'_x000C_',
		'_x000E_',
		'_x000F_',
		'_x0010_',
		'_x0011_',
		'_x0012_',
		'_x0013_',
		'_x0014_',
		'_x0015_',
		'_x0016_',
		'_x0017_',
		'_x0018_',
		'_x0019_',
		'_x001A_',
		'_x001B_',
		'_x001C_',
		'_x001D_',
		'_x001E_',
		'_x001F_',
	];

	/**
	 * SYLK Characters array.
	 */
	private const SYLK_CHARACTERS = [
		"\x1B 0" => "\x00",
		"\x1B 1" => "\x01",
		"\x1B 2" => "\x02",
		"\x1B 3" => "\x03",
		"\x1B 4" => "\x04",
		"\x1B 5" => "\x05",
		"\x1B 6" => "\x06",
		"\x1B 7" => "\x07",
		"\x1B 8" => "\x08",
		"\x1B 9" => "\x09",
		"\x1B :" => "\x0a",
		"\x1B ;" => "\x0b",
		"\x1B <" => "\x0c",
		"\x1B =" => "\x0d",
		"\x1B >" => "\x0e",
		"\x1B ?" => "\x0f",
		"\x1B!0" => "\x10",
		"\x1B!1" => "\x11",
		"\x1B!2" => "\x12",
		"\x1B!3" => "\x13",
		"\x1B!4" => "\x14",
		"\x1B!5" => "\x15",
		"\x1B!6" => "\x16",
		"\x1B!7" => "\x17",
		"\x1B!8" => "\x18",
		"\x1B!9" => "\x19",
		"\x1B!:" => "\x1a",
		"\x1B!;" => "\x1b",
		"\x1B!<" => "\x1c",
		"\x1B!=" => "\x1d",
		"\x1B!>" => "\x1e",
		"\x1B!?" => "\x1f",
		"\x1B'?" => "\x7f",
		"\x1B(0" => '€', // 128 in CP1252
		"\x1B(2" => '‚', // 130 in CP1252
		"\x1B(3" => 'ƒ', // 131 in CP1252
		"\x1B(4" => '„', // 132 in CP1252
		"\x1B(5" => '…', // 133 in CP1252
		"\x1B(6" => '†', // 134 in CP1252
		"\x1B(7" => '‡', // 135 in CP1252
		"\x1B(8" => 'ˆ', // 136 in CP1252
		"\x1B(9" => '‰', // 137 in CP1252
		"\x1B(:" => 'Š', // 138 in CP1252
		"\x1B(;" => '‹', // 139 in CP1252
		"\x1BNj" => 'Œ', // 140 in CP1252
		"\x1B(>" => 'Ž', // 142 in CP1252
		"\x1B)1" => '‘', // 145 in CP1252
		"\x1B)2" => '’', // 146 in CP1252
		"\x1B)3" => '“', // 147 in CP1252
		"\x1B)4" => '”', // 148 in CP1252
		"\x1B)5" => '•', // 149 in CP1252
		"\x1B)6" => '–', // 150 in CP1252
		"\x1B)7" => '—', // 151 in CP1252
		"\x1B)8" => '˜', // 152 in CP1252
		"\x1B)9" => '™', // 153 in CP1252
		"\x1B):" => 'š', // 154 in CP1252
		"\x1B);" => '›', // 155 in CP1252
		"\x1BNz" => 'œ', // 156 in CP1252
		"\x1B)>" => 'ž', // 158 in CP1252
		"\x1B)?" => 'Ÿ', // 159 in CP1252
		"\x1B*0" => ' ', // 160 in CP1252
		"\x1BN!" => '¡', // 161 in CP1252
		"\x1BN\"" => '¢', // 162 in CP1252
		"\x1BN#" => '£', // 163 in CP1252
		"\x1BN(" => '¤', // 164 in CP1252
		"\x1BN%" => '¥', // 165 in CP1252
		"\x1B*6" => '¦', // 166 in CP1252
		"\x1BN'" => '§', // 167 in CP1252
		"\x1BNH " => '¨', // 168 in CP1252
		"\x1BNS" => '©', // 169 in CP1252
		"\x1BNc" => 'ª', // 170 in CP1252
		"\x1BN+" => '«', // 171 in CP1252
		"\x1B*<" => '¬', // 172 in CP1252
		"\x1B*=" => '­', // 173 in CP1252
		"\x1BNR" => '®', // 174 in CP1252
		"\x1B*?" => '¯', // 175 in CP1252
		"\x1BN0" => '°', // 176 in CP1252
		"\x1BN1" => '±', // 177 in CP1252
		"\x1BN2" => '²', // 178 in CP1252
		"\x1BN3" => '³', // 179 in CP1252
		"\x1BNB " => '´', // 180 in CP1252
		"\x1BN5" => 'µ', // 181 in CP1252
		"\x1BN6" => '¶', // 182 in CP1252
		"\x1BN7" => '·', // 183 in CP1252
		"\x1B+8" => '¸', // 184 in CP1252
		"\x1BNQ" => '¹', // 185 in CP1252
		"\x1BNk" => 'º', // 186 in CP1252
		"\x1BN;" => '»', // 187 in CP1252
		"\x1BN<" => '¼', // 188 in CP1252
		"\x1BN=" => '½', // 189 in CP1252
		"\x1BN>" => '¾', // 190 in CP1252
		"\x1BN?" => '¿', // 191 in CP1252
		"\x1BNAA" => 'À', // 192 in CP1252
		"\x1BNBA" => 'Á', // 193 in CP1252
		"\x1BNCA" => 'Â', // 194 in CP1252
		"\x1BNDA" => 'Ã', // 195 in CP1252
		"\x1BNHA" => 'Ä', // 196 in CP1252
		"\x1BNJA" => 'Å', // 197 in CP1252
		"\x1BNa" => 'Æ', // 198 in CP1252
		"\x1BNKC" => 'Ç', // 199 in CP1252
		"\x1BNAE" => 'È', // 200 in CP1252
		"\x1BNBE" => 'É', // 201 in CP1252
		"\x1BNCE" => 'Ê', // 202 in CP1252
		"\x1BNHE" => 'Ë', // 203 in CP1252
		"\x1BNAI" => 'Ì', // 204 in CP1252
		"\x1BNBI" => 'Í', // 205 in CP1252
		"\x1BNCI" => 'Î', // 206 in CP1252
		"\x1BNHI" => 'Ï', // 207 in CP1252
		"\x1BNb" => 'Ð', // 208 in CP1252
		"\x1BNDN" => 'Ñ', // 209 in CP1252
		"\x1BNAO" => 'Ò', // 210 in CP1252
		"\x1BNBO" => 'Ó', // 211 in CP1252
		"\x1BNCO" => 'Ô', // 212 in CP1252
		"\x1BNDO" => 'Õ', // 213 in CP1252
		"\x1BNHO" => 'Ö', // 214 in CP1252
		"\x1B-7" => '×', // 215 in CP1252
		"\x1BNi" => 'Ø', // 216 in CP1252
		"\x1BNAU" => 'Ù', // 217 in CP1252
		"\x1BNBU" => 'Ú', // 218 in CP1252
		"\x1BNCU" => 'Û', // 219 in CP1252
		"\x1BNHU" => 'Ü', // 220 in CP1252
		"\x1B-=" => 'Ý', // 221 in CP1252
		"\x1BNl" => 'Þ', // 222 in CP1252
		"\x1BN{" => 'ß', // 223 in CP1252
		"\x1BNAa" => 'à', // 224 in CP1252
		"\x1BNBa" => 'á', // 225 in CP1252
		"\x1BNCa" => 'â', // 226 in CP1252
		"\x1BNDa" => 'ã', // 227 in CP1252
		"\x1BNHa" => 'ä', // 228 in CP1252
		"\x1BNJa" => 'å', // 229 in CP1252
		"\x1BNq" => 'æ', // 230 in CP1252
		"\x1BNKc" => 'ç', // 231 in CP1252
		"\x1BNAe" => 'è', // 232 in CP1252
		"\x1BNBe" => 'é', // 233 in CP1252
		"\x1BNCe" => 'ê', // 234 in CP1252
		"\x1BNHe" => 'ë', // 235 in CP1252
		"\x1BNAi" => 'ì', // 236 in CP1252
		"\x1BNBi" => 'í', // 237 in CP1252
		"\x1BNCi" => 'î', // 238 in CP1252
		"\x1BNHi" => 'ï', // 239 in CP1252
		"\x1BNs" => 'ð', // 240 in CP1252
		"\x1BNDn" => 'ñ', // 241 in CP1252
		"\x1BNAo" => 'ò', // 242 in CP1252
		"\x1BNBo" => 'ó', // 243 in CP1252
		"\x1BNCo" => 'ô', // 244 in CP1252
		"\x1BNDo" => 'õ', // 245 in CP1252
		"\x1BNHo" => 'ö', // 246 in CP1252
		"\x1B/7" => '÷', // 247 in CP1252
		"\x1BNy" => 'ø', // 248 in CP1252
		"\x1BNAu" => 'ù', // 249 in CP1252
		"\x1BNBu" => 'ú', // 250 in CP1252
		"\x1BNCu" => 'û', // 251 in CP1252
		"\x1BNHu" => 'ü', // 252 in CP1252
		"\x1B/=" => 'ý', // 253 in CP1252
		"\x1BN|" => 'þ', // 254 in CP1252
		"\x1BNHy" => 'ÿ', // 255 in CP1252
	];

	/**
	 * Decimal separator.
	 */
	protected static ?string $decimalSeparator = null;

	/**
	 * Thousands separator.
	 */
	protected static ?string $thousandsSeparator = null;

	/**
	 * Currency code.
	 */
	protected static ?string $currencyCode = null;

	/**
	 * Is iconv extension available?
	 */
	protected static ?bool $isIconvEnabled = null;

	/**
	 * iconv options.
	 */
	protected static string $iconvOptions = '//IGNORE//TRANSLIT';

	/** @var string[] */
	protected static array $iconvOptionsArray = ['//IGNORE//TRANSLIT', '//IGNORE'];

	/** @internal */
	protected static string $iconvName = 'iconv';

	/** @internal */
	protected static bool $iconvTest2 = false;

	/** @internal */
	protected static bool $iconvTest3 = false;

	/**
	 * Get whether iconv extension is available.
	 */
	public static function getIsIconvEnabled(): bool
	{
		if (isset(static::$isIconvEnabled)) {
			return static::$isIconvEnabled;
		}

		// Assume no problems with iconv
		static::$isIconvEnabled = true;

		// Fail if iconv doesn't exist
		if (!function_exists(static::$iconvName)) {
			static::$isIconvEnabled = false;
		} elseif (static::$iconvTest2 || !@iconv('UTF-8', 'UTF-16LE', 'x')) {
			// Sometimes iconv is not working, and e.g. iconv('UTF-8', 'UTF-16LE', 'x') just returns false,
			static::$isIconvEnabled = false;
		} elseif (static::$iconvTest3 || (defined('PHP_OS') && @stristr(PHP_OS, 'AIX') && defined('ICONV_IMPL') && (@strcasecmp(ICONV_IMPL, 'unknown') == 0) && defined('ICONV_VERSION') && (@strcasecmp(ICONV_VERSION, 'unknown') == 0))) {
			// CUSTOM: IBM AIX iconv() does not work
			static::$isIconvEnabled = false;
		}

		// Deactivate iconv default options if they fail (as seen on IBM i-series)
		if (static::$isIconvEnabled) {
			static::$iconvOptions = '';
			foreach (static::$iconvOptionsArray as $option) {
				if (@iconv('UTF-8', 'UTF-16LE' . $option, 'x') !== false) {
					static::$iconvOptions = $option;

					break;
				}
			}
		}

		return static::$isIconvEnabled;
	}

	/**
	 * Convert from OpenXML escaped control character to PHP control character.
	 *
	 * Excel 2007 team:
	 * ----------------
	 * That's correct, control characters are stored directly in the shared-strings table.
	 * We do encode characters that cannot be represented in XML using the following escape sequence:
	 * _xHHHH_ where H represents a hexadecimal character in the character's value...
	 * So you could end up with something like _x0008_ in a string (either in a cell value (<v>)
	 * element or in the shared string <t> element.
	 *
	 * @param string $textValue Value to unescape
	 */
	public static function controlCharacterOOXML2PHP(string $textValue): string
	{
		return Preg::replaceCallback('/_x[0-9A-F]{4}_(_xD[CDEF][0-9A-F]{2}_)?/', \Closure::fromCallable([self::class, 'toOutChar']), $textValue);
	}

	private static function toHexVal(string $char): int
	{
		if ($char >= '0' && $char <= '9') {
			return ord($char) - ord('0');
		}

		return ord($char) - ord('A') + 10;
	}

	/** @param array<?string> $match */
	private static function toOutChar(array $match): string
	{
		/** @var string */
		$chars = $match[0];
		$h = ((self::toHexVal($chars[2]) << 12)
			| (self::toHexVal($chars[3]) << 8)
			| (self::toHexVal($chars[4]) << 4)
			| (self::toHexVal($chars[5])));
		if (strlen($chars) === 7) { // no low surrogate
			if ($chars[2] === 'D' && in_array($chars[3], ['8', '9', 'A', 'B', 'C', 'D', 'E', 'F'], true)) {
				return '�';
			}

			return mb_chr($h, 'UTF-8');
		}
		if ($chars[2] === 'D' && in_array($chars[3], ['C', 'D', 'D', 'F'], true)) {
			return '�'; // Excel interprets as one substitute, not 2
		}
		if ($chars[2] !== 'D' || !in_array($chars[3], ['8', '9', 'A', 'B'], true)) {
			return mb_chr($h, 'UTF-8') . '�';
		}
		$l = ((self::toHexVal($chars[9]) << 12)
			| (self::toHexVal($chars[10]) << 8)
			| (self::toHexVal($chars[11]) << 4)
			| (self::toHexVal($chars[12])));
		$result = 0x10000 + ($h - 0xD800) * 0x400 + ($l - 0xDC00);

		return mb_chr($result, 'UTF-8');
	}

	/**
	 * Convert from PHP control character to OpenXML escaped control character.
	 *
	 * Excel 2007 team:
	 * ----------------
	 * That's correct, control characters are stored directly in the shared-strings table.
	 * We do encode characters that cannot be represented in XML using the following escape sequence:
	 * _xHHHH_ where H represents a hexadecimal character in the character's value...
	 * So you could end up with something like _x0008_ in a string (either in a cell value (<v>)
	 * element or in the shared string <t> element.
	 *
	 * @param string $textValue Value to escape
	 */
	public static function controlCharacterPHP2OOXML(string $textValue): string
	{
		$textValue = Preg::replace('/_(x[0-9A-F]{4}_)/', '_x005F_$1', $textValue);

		return str_replace(self::CONTROL_CHARACTERS_KEYS, self::CONTROL_CHARACTERS_VALUES, $textValue);
	}

	/**
	 * Try to sanitize UTF8, replacing invalid sequences with Unicode substitution characters.
	 */
	public static function sanitizeUTF8(string $textValue): string
	{
		$textValue = str_replace(["\xef\xbf\xbe", "\xef\xbf\xbf"], "\xef\xbf\xbd", $textValue);
		$subst = mb_substitute_character(); // default is question mark
		mb_substitute_character(65533); // Unicode substitution character
		$returnValue = (string) mb_convert_encoding($textValue, 'UTF-8', 'UTF-8');
		mb_substitute_character($subst);

		return $returnValue;
	}

	/**
	 * Check if a string contains UTF8 data.
	 */
	public static function isUTF8(string $textValue): bool
	{
		return $textValue === self::sanitizeUTF8($textValue);
	}

	/**
				 * Formats a numeric value as a string for output in various output writers forcing
				 * point as decimal separator in case locale is other than English.
				 * @param float|int|string|null $numericValue
				 */
				public static function formatNumber($numericValue): string
	{
		if (is_float($numericValue)) {
			return str_replace(',', '.', (string) $numericValue);
		}

		return (string) $numericValue;
	}

	/**
	 * Converts a UTF-8 string into BIFF8 Unicode string data (8-bit string length)
	 * Writes the string using uncompressed notation, no rich text, no Asian phonetics
	 * If mbstring extension is not available, ASCII is assumed, and compressed notation is used
	 * although this will give wrong results for non-ASCII strings
	 * see OpenOffice.org's Documentation of the Microsoft Excel File Format, sect. 2.5.3.
	 *
	 * @param string $textValue UTF-8 encoded string
	 * @param array<int, array{strlen: int, fontidx: int}> $arrcRuns Details of rich text runs in $value
	 */
	public static function UTF8toBIFF8UnicodeShort(string $textValue, array $arrcRuns = []): string
	{
		// character count
		$ln = self::countCharacters($textValue, 'UTF-8');
		// option flags
		if (empty($arrcRuns)) {
			$data = pack('CC', $ln, 0x0001);
			// characters
			$data .= self::convertEncoding($textValue, 'UTF-16LE', 'UTF-8');
		} else {
			$data = pack('vC', $ln, 0x09);
			$data .= pack('v', count($arrcRuns));
			// characters
			$data .= self::convertEncoding($textValue, 'UTF-16LE', 'UTF-8');
			foreach ($arrcRuns as $cRun) {
				$data .= pack('v', $cRun['strlen']);
				$data .= pack('v', $cRun['fontidx']);
			}
		}

		return $data;
	}

	/**
	 * Converts a UTF-8 string into BIFF8 Unicode string data (16-bit string length)
	 * Writes the string using uncompressed notation, no rich text, no Asian phonetics
	 * If mbstring extension is not available, ASCII is assumed, and compressed notation is used
	 * although this will give wrong results for non-ASCII strings
	 * see OpenOffice.org's Documentation of the Microsoft Excel File Format, sect. 2.5.3.
	 *
	 * @param string $textValue UTF-8 encoded string
	 */
	public static function UTF8toBIFF8UnicodeLong(string $textValue): string
	{
		// characters
		$chars = self::convertEncoding($textValue, 'UTF-16LE', 'UTF-8');
		$ln = (int) (strlen($chars) / 2);  // N.B. - strlen, not mb_strlen issue #642

		return pack('vC', $ln, 0x0001) . $chars;
	}

	/**
	 * Convert string from one encoding to another.
	 *
	 * @param string $to Encoding to convert to, e.g. 'UTF-8'
	 * @param string $from Encoding to convert from, e.g. 'UTF-16LE'
	 */
	public static function convertEncoding(string $textValue, string $to, string $from, ?string $options = null): string
	{
		if (static::getIsIconvEnabled()) {
			$result = iconv($from, $to . ($options ?? static::$iconvOptions), $textValue);
			if (false !== $result) {
				return $result;
			}
		}

		return (string) mb_convert_encoding($textValue, $to, $from);
	}

	/**
	 * Get character count.
	 *
	 * @param string $encoding Encoding
	 *
	 * @return int Character count
	 */
	public static function countCharacters(string $textValue, string $encoding = 'UTF-8'): int
	{
		return mb_strlen($textValue, $encoding);
	}

	/**
	 * Get character count using mb_strwidth rather than mb_strlen.
	 *
	 * @param string $encoding Encoding
	 *
	 * @return int Character count
	 */
	public static function countCharactersDbcs(string $textValue, string $encoding = 'UTF-8'): int
	{
		return mb_strwidth($textValue, $encoding);
	}

	/**
	 * Get a substring of a UTF-8 encoded string.
	 *
	 * @param string $textValue UTF-8 encoded string
	 * @param int $offset Start offset
	 * @param ?int $length Maximum number of characters in substring
	 */
	public static function substring(string $textValue, int $offset, ?int $length = 0): string
	{
		return mb_substr($textValue, $offset, $length, 'UTF-8');
	}

	/**
	 * Convert a UTF-8 encoded string to upper case.
	 *
	 * @param string $textValue UTF-8 encoded string
	 */
	public static function strToUpper(string $textValue): string
	{
		return mb_convert_case($textValue, MB_CASE_UPPER, 'UTF-8');
	}

	/**
	 * Convert a UTF-8 encoded string to lower case.
	 *
	 * @param string $textValue UTF-8 encoded string
	 */
	public static function strToLower(string $textValue): string
	{
		return mb_convert_case($textValue, MB_CASE_LOWER, 'UTF-8');
	}

	/**
	 * Convert a UTF-8 encoded string to title/proper case
	 * (uppercase every first character in each word, lower case all other characters).
	 *
	 * @param string $textValue UTF-8 encoded string
	 */
	public static function strToTitle(string $textValue): string
	{
		return mb_convert_case($textValue, MB_CASE_TITLE, 'UTF-8');
	}

	public static function mbIsUpper(string $character): bool
	{
		return mb_strtolower($character, 'UTF-8') !== $character;
	}

	/**
	 * Splits a UTF-8 string into an array of individual characters.
	 *
	 * @return string[]
	 */
	public static function mbStrSplit(string $string): array
	{
		// Split at all position not after the start: ^
		// and not before the end: $
		$split = Preg::split('/(?<!^)(?!$)/u', $string);

		return $split;
	}

	/**
	 * Reverse the case of a string, so that all uppercase characters become lowercase
	 * and all lowercase characters become uppercase.
	 *
	 * @param string $textValue UTF-8 encoded string
	 */
	public static function strCaseReverse(string $textValue): string
	{
		$characters = self::mbStrSplit($textValue);
		foreach ($characters as &$character) {
			if (self::mbIsUpper($character)) {
				$character = mb_strtolower($character, 'UTF-8');
			} else {
				$character = mb_strtoupper($character, 'UTF-8');
			}
		}

		return implode('', $characters);
	}

	private static function useAlt(string $altValue, string $default, bool $trimAlt): string
	{
		return ($trimAlt ? trim($altValue) : $altValue) ?: $default;
	}

	private static function getLocaleValue(string $key, string $altKey, string $default, bool $trimAlt = false): string
	{
		/** @var string[] */
		$localeconv = localeconv();
		$rslt = $localeconv[$key];
		// win-1252 implements Euro as 0x80 plus other symbols
		// Not suitable for Composer\Pcre\Preg
		if (preg_match('//u', $rslt) !== 1) {
			$rslt = '';
		}

		return $rslt ?: self::useAlt($localeconv[$altKey], $default, $trimAlt);
	}

	/**
	 * Get the decimal separator. If it has not yet been set explicitly, try to obtain number
	 * formatting information from locale.
	 */
	public static function getDecimalSeparator(): string
	{
		if (!isset(static::$decimalSeparator)) {
			static::$decimalSeparator = self::getLocaleValue('decimal_point', 'mon_decimal_point', '.');
		}

		return static::$decimalSeparator;
	}

	/**
	 * Set the decimal separator. Only used by NumberFormat::toFormattedString()
	 * to format output by \PhpOffice\PhpSpreadsheet\Writer\Html and \PhpOffice\PhpSpreadsheet\Writer\Pdf.
	 *
	 * @param ?string $separator Character for decimal separator
	 */
	public static function setDecimalSeparator(?string $separator): void
	{
		static::$decimalSeparator = $separator;
	}

	/**
	 * Get the thousands separator. If it has not yet been set explicitly, try to obtain number
	 * formatting information from locale.
	 */
	public static function getThousandsSeparator(): string
	{
		if (!isset(static::$thousandsSeparator)) {
			static::$thousandsSeparator = self::getLocaleValue('thousands_sep', 'mon_thousands_sep', ',');
		}

		return static::$thousandsSeparator;
	}

	/**
	 * Set the thousands separator. Only used by NumberFormat::toFormattedString()
	 * to format output by \PhpOffice\PhpSpreadsheet\Writer\Html and \PhpOffice\PhpSpreadsheet\Writer\Pdf.
	 *
	 * @param ?string $separator Character for thousands separator
	 */
	public static function setThousandsSeparator(?string $separator): void
	{
		static::$thousandsSeparator = $separator;
	}

	/**
	 *    Get the currency code. If it has not yet been set explicitly, try to obtain the
	 *        symbol information from locale.
	 */
	public static function getCurrencyCode(bool $trimAlt = false): string
	{
		if (!isset(static::$currencyCode)) {
			static::$currencyCode = self::getLocaleValue('currency_symbol', 'int_curr_symbol', '$', $trimAlt);
		}

		return static::$currencyCode;
	}

	/**
	 * Set the currency code. Only used by NumberFormat::toFormattedString()
	 *        to format output by \PhpOffice\PhpSpreadsheet\Writer\Html and \PhpOffice\PhpSpreadsheet\Writer\Pdf.
	 *
	 * @param ?string $currencyCode Character for currency code
	 */
	public static function setCurrencyCode(?string $currencyCode): void
	{
		static::$currencyCode = $currencyCode;
	}

	/**
	 * Convert SYLK encoded string to UTF-8.
	 *
	 * @param string $textValue SYLK encoded string
	 *
	 * @return string UTF-8 encoded string
	 */
	public static function SYLKtoUTF8(string $textValue): string
	{
		// If there is no escape character in the string there is nothing to do
		if (!str_contains($textValue, "\x1b")) {
			return $textValue;
		}

		foreach (self::SYLK_CHARACTERS as $k => $v) {
			$textValue = str_replace($k, $v, $textValue);
		}

		return $textValue;
	}

	/**
	 * Retrieve any leading numeric part of a string, or return the full string if no leading numeric
	 * (handles basic integer or float, but not exponent or non decimal).
	 *
	 * @return float|string string or only the leading numeric part of the string
	 */
	public static function testStringAsNumeric(string $textValue)
	{
		if (is_numeric($textValue)) {
			return $textValue;
		}
		$v = (float) $textValue;

		return (is_numeric(substr($textValue, 0, strlen((string) $v)))) ? $v : $textValue;
	}

	public static function strlenAllowNull(?string $string): int
	{
		return strlen("$string");
	}

	/**
				 * @param bool $convertBool If true, convert bool to locale-aware TRUE/FALSE rather than 1/null-string
				 * @param bool $lessFloatPrecision If true, floats will be converted to a more human-friendly but less computationally accurate value
				 * @param mixed $value
				 */
				public static function convertToString($value, bool $throw = true, string $default = '', bool $convertBool = false, bool $lessFloatPrecision = false): string
	{
		if ($convertBool && is_bool($value)) {
			return $value ? Calculation::getTRUE() : Calculation::getFALSE();
		}
		if (is_float($value) && !$lessFloatPrecision) {
			$string = (string) $value;
			// look out for scientific notation
			if (!Preg::isMatch('/[^-+0-9.]/', $string)) {
				$minus = $value < 0 ? '-' : '';
				$positive = abs($value);
				$floor = floor($positive);
				$oldFrac = (string) ($positive - $floor);
				$frac = Preg::replace('/^0[.](\d+)$/', '$1', $oldFrac);
				if ($frac !== $oldFrac) {
					return "$minus$floor.$frac";
				}
			}

			return $string;
		}
		if ($value === null || is_scalar($value) || is_object($value) && method_exists($value, '__toString')) {
			return (string) $value;
		}

		if ($throw) {
			throw new SpreadsheetException('Unable to convert to string');
		}

		return $default;
	}

	/**
	 * Assist with POST items when samples are run in browser.
	 * Never run as part of unit tests, which are command line.
	 *
	 * @codeCoverageIgnore
	 */
	public static function convertPostToString(string $index, string $default = ''): string
	{
		if (isset($_POST[$index])) {
			return htmlentities(self::convertToString($_POST[$index], false, $default));
		}

		return $default;
	}

	/**
	 * Php introduced str_increment with Php8.3,
	 * but didn't issue deprecation notices till 8.5.
	 *
	 * @param-out string $str
	 *
	 * @codeCoverageIgnore
	 */
	public static function stringIncrement(string &$str): string
	{
		if (function_exists('str_increment')) {
			/** @var non-empty-string $str */
			$str2 = str_increment($str);
		} else {
			$str1 = $str;
			/**
			 * This is an outright lie, but I don't know how else to satisfy Phpstan for Php8.5+.
			 *
			 * @var numeric-string $str1
			 */
			++$str1;
			$str2 = "$str1";
		}

		/**
		 * This is demonstrably the case. I don't know why Phpstan thinks $str2 is mixed at this point.
		 *
		 * @var string $str2 set above by str_increment or ="..."
		 */
		$str = $str2;

		return $str;
	}

	/** @internal */
	protected static string $testClass = IntlCalendar::class;

	/**
	 * Set all of currencyCode, thousandsSeparator, decimalSeparator,
	 * and Calculation locale with a single call.
	 * The main point here is avoid the use of Php setlocale,
	 * which is not threadsafe. It uses the Intl extension instead,
	 * which is not a requirement for PhpSpreadsheet.
	 * Because of that, the function returns a bool which will
	 * be false if Intl is not available, or the supplied locale
	 * is not valid according to Intl.
	 */
	public static function setLocale(?string $locale): bool
	{
		if ($locale === null) {
			self::$currencyCode = null;
			self::$thousandsSeparator = null;
			self::$decimalSeparator = null;
			Calculation::getInstance()->setLocale('en_us');

			return true;
		}
		$localeCalc = $locale;
		if (Preg::isMatch('/^([a-z][a-z])_([a-z][a-z])(?:[.]utf-8)?$/i', $locale, $matches)) {
			$locale = strtolower($matches[1]) . '_' . strtoupper($matches[2]);
			$localeCalc = strtolower($matches[1]) . '_' . strtolower($matches[2]);
		}
		if (!class_exists(static::$testClass)) {
			return false;
		}
		// NumberFormatter constructor succeeds even with
		// bad locale before Php8.4, so try to validate
		// the locale beforehand.
		$locales = IntlCalendar::getAvailableLocales();
		if (!in_array($locale, $locales, true)) {
			return false;
		}
		$formatter = new NumberFormatter(
			$locale,
			NumberFormatter::CURRENCY
		);
		$currency = $formatter->getSymbol(
			NumberFormatter::CURRENCY_SYMBOL
		);
		$formatter = new NumberFormatter(
			$locale,
			NumberFormatter::DECIMAL
		);
		$thousands = $formatter->getSymbol(
			NumberFormatter::GROUPING_SEPARATOR_SYMBOL
		);
		$decimal = $formatter->getSymbol(
			NumberFormatter::DECIMAL_SEPARATOR_SYMBOL
		);
		self::$currencyCode = $currency;
		self::$thousandsSeparator = $thousands;
		self::$decimalSeparator = $decimal;
		Calculation::getInstance()->setLocale($localeCalc);

		return true;
	}
}

```