mb_convert_case()

mb_convert_case() — Perform case folding on a string.

Built-in function of PHP 8.5. The manual lists it as available in PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

What it does

Performs case folding on a string, converted in the way specified by mode.

Signature

mb_convert_case(string $string, int $mode, ?string $encoding = null): string

Parameters

ParameterTypeWhat it takes
$stringstringThe string being converted.
$modeintThe mode of the conversion. It can be one of MB_CASE_UPPER, MB_CASE_LOWER, MB_CASE_TITLE, MB_CASE_FOLD, MB_CASE_UPPER_SIMPLE, MB_CASE_LOWER_SIMPLE, MB_CASE_TITLE_SIMPLE, MB_CASE_FOLD_SIMPLE.
$encoding?stringThe encoding parameter is the character encoding. If it is omitted or null, the internal character encoding value will be used.

Return value

A case folded version of string converted in the way specified by mode.

Example

A runnable snippet:

$str = "mary had a Little lamb and she loved it so"; $str = mb_convert_case($str, MB_CASE_UPPER, "UTF-8"); echo $str, PHP_EOL; $str = mb_convert_case($str, MB_CASE_TITLE, "UTF-8"); echo $str, PHP_EOL;

Changelog

VersionChange
8.3.0Implemented conditional casing rules for the Greek letter sigma which only apply to MB_CASE_LOWER and MB_CASE_TITLE modes, not to MB_CASE_LOWER_SIMPLE and MB_CASE_TITLE_SIMPLE.
8.0.0Now throws a ValueError if encoding is an invalid encoding. Previously, an E_WARNING was emitted and false was returned.
7.3.0Added support for MB_CASE_FOLD, MB_CASE_UPPER_SIMPLE, MB_CASE_LOWER_SIMPLE, MB_CASE_TITLE_SIMPLE, and MB_CASE_FOLD_SIMPLE as mode.

See also

mb_strtolower(), mb_strtoupper(), strtolower(), strtoupper(), ucfirst(), ucwords()

All PHP 8.5 built-in functions

Reference card built from the PHP manual page mb_convert_case() (PHP documentation, CC BY 3.0). The page is generated from the manual, so the wording of the parameter and return value text follows php.net.