strtolower()
strtolower() — Make a string lowercase.
Built-in function of PHP 8.5. The manual lists it as available in PHP 4, 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
Returns string with all ASCII alphabetic characters converted to lowercase.
Signature
strtolower(string $string): string
Parameters
| Parameter | Type | What it takes |
|---|---|---|
| $string | string | The input string. |
Return value
Returns the lowercased string.
Example
A runnable snippet:
$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
Changelog
| Version | Change |
|---|---|
| 8.2.0 | Case conversion no longer depends on the locale set with setlocale(). Only ASCII characters will be converted. |
See also
strtoupper(), ucfirst(), ucwords(), mb_strtolower()
All PHP 8.5 built-in functions
Reference card built from the PHP manual page strtolower() (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.