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PHP: strtolower() function

Description

The strtolower() function is used to convert all alphabetic characters of a string to lowercase.

Version:

(PHP 4 and above)

Syntax:

strtolower(string1)

Parameter:

Name Description Required /
Optional		 Type
string1 The input string. Required string

Return value:

Returns the lowercased string.

Value Type: string.

Pictorial Presentation

string_strtolower

Example: 

<?php
$string1="WELCOME TO W3RESOURCE.COM";
echo strtolower($string1); 
?>

Output:

welcome to w3resource.com

View the example in the browser

See also

PHP Function Reference

Previous: strstr
Next: strtoupper



PHP: Tips of the Day

In PHP, there are two versions of logical AND and OR operators.

Operator True if
$a and $b Both $a and $b are true
$a && $b Both $a and $b are true
$a or $b Either $a or $b is true
$a || $b Either $a or $b is true

Note that the && and || opererators have higher precedence than and and or. See table below:

Evaluation Result of $e Evaluated as
$e = false || true True $e = (false || true)
$e = false or true False ($e = false) or true

Because of this it's safer to use && and || instead of and and or.