PHP Manual: Make a string lowercase

Description

string mb_strtolower(string $string, stringnull $encoding = null)

Returns string with all alphabetic characters converted to lowercase.

Parameters

string: The string being lowercased.
encoding: The encoding parameter is the character encoding. If it is omitted or null, the internal character encoding value will be used.

Return Values

string with all alphabetic characters converted to lowercase.

Changelog

Version	Description
8.3.0	Implemented conditional casing rules for the Greek letter sigma.

Examples

Example #1 mb_strtolower example

<?php
$str = "Mary Had A Little Lamb and She LOVED It So";
$str = mb_strtolower($str);
echo $str; // Prints mary had a little lamb and she loved it so
?>

Example #2 mb_strtolower example with non-Latin UTF-8 text

<?php
$str = "Τάχιστη αλώπηξ βαφής ψημένη γη, δρασκελίζει υπέρ νωθρού κυνός";
$str = mb_strtolower($str, 'UTF-8');
echo $str; // Prints τάχιστη αλώπηξ βαφής ψημένη γη, δρασκελίζει υπέρ νωθρού κυνός
?>

Notes

By contrast to strtolower, 'alphabetic' is determined by the Unicode character properties. Thus the behaviour of this function is not affected by locale settings and it can convert any characters that have 'alphabetic' property, such as a-umlaut (ä).

For more information about the Unicode properties, please see » http://www.unicode.org/reports/tr21/.

mb_strtolower