PHP Manual: Binary safe string comparison of the first n characters

Description

int strncmp(string $string1, string $string2, int $length)

This function is similar to strcmp, with the difference that you can specify the (upper limit of the) number of characters from each string to be used in the comparison.

Note that this comparison is case sensitive.

Parameters

string1: The first string.
string2: The second string.
length: Number of characters to use in the comparison.

Return Values

Returns a value less than 0 if string1 is less than string2; a value greater than 0 if string1 is greater than string2, and 0 if they are equal. No particular meaning can be reliably inferred from the value aside from its sign.

Changelog

Version	Description
8.2.0	This function is no longer guaranteed to return `strlen($string1) - strlen($string2)` when string lengths are not equal, but may now return `-1` or `1` instead.

Examples

Example #1 strncmp example

<?php

$var1 = 'Hello John';
$var2 = 'Hello Doe';
if (strncmp($var1, $var2, 5) === 0) {
    echo 'First 5 characters of $var1 and $var2 are equal in a case-sensitive string comparison';
}
?>

strncmp

Description

Parameters

Return Values

Changelog

Examples

See Also