array ( 0 => 'index.php', 1 => 'PHP Manual', ), 'head' => array ( 0 => 'UTF-8', 1 => 'en', ), 'this' => array ( 0 => 'function.strtolower.php', 1 => 'strtolower', 2 => 'Make a string lowercase', ), 'up' => array ( 0 => 'ref.strings.php', 1 => 'String Functions', ), 'prev' => array ( 0 => 'function.strtok.php', 1 => 'strtok', ), 'next' => array ( 0 => 'function.strtoupper.php', 1 => 'strtoupper', ), 'alternatives' => array ( ), 'source' => array ( 'lang' => 'en', 'path' => 'reference/strings/functions/strtolower.xml', ), 'history' => array ( ), ); $setup["toc"] = $TOC; $setup["toc_deprecated"] = $TOC_DEPRECATED; $setup["parents"] = $PARENTS; manual_setup($setup); contributors($setup); ?>

strtolower

(PHP 4, PHP 5, PHP 7, PHP 8)

strtolower — Make a string lowercase

Description

strtolower(string $string): string

Returns string with all ASCII alphabetic characters converted to lowercase.

Bytes in the range "A" (0x41) to "Z" (0x5a) will be converted to the corresponding lowercase letter by adding 32 to each byte value.

This can be used to convert ASCII characters within strings encoded with UTF-8, since multibyte UTF-8 characters will be ignored. To convert multibyte non-ASCII characters, use mb_strtolower().

Parameters

string

The input string.

Return Values

Returns the lowercased string.

Changelog

Version Description
8.2.0 Case conversion no longer depends on the locale set with setlocale(). Only ASCII characters will be converted.

Examples

Example #1 strtolower() example

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

Notes

Note: This function is binary-safe.

See Also