PHP reference

strcasecmp

Compares two strings, ignoring case.

Syntax

strcasecmp(string $string1, string $string2): int

Parameter	Type	Description
$string1	string	The first string.
$string2	string	The second string.

int`0` if the strings are equal; a negative or positive number if the first is smaller or greater.

Equality regardless of case:

<?php
 
var_dump(strcasecmp('Hello', 'HELLO') === 0);

Output:

bool(true)

Sorting regardless of case:

<?php
 
$names = ['bob', 'Anna', 'carl'];
usort($names, 'strcasecmp');
 
echo implode(', ', $names);

Output:

Anna, bob, carl

Case is ignored for ASCII letters only. For other alphabets compare the results of mb_strtolower().

Strings — Working with strings in PHP — quotes, concatenation, length, searching, replacing and multibyte functions.