substr_compare

(PHP 5, PHP 7)

Binary safe comparison of two strings from an offset, up to length characters

int substr_compare ( string $main_str, string $str, int $offset [, int $length [, bool $case_insensitivity = false ]] )

substr_compare() compares main_str from position offset with str up to length characters.

Parameters:

main_str

The main string being compared.

str

The secondary string being compared.

offset

The start position for the comparison. If negative, it starts counting from the end of the string.

length

The length of the comparison. The default value is the largest of the length of the str compared to the length of main_str less the offset.

case_insensitivity

If case_insensitivity is TRUE, comparison is case insensitive.

Returns:

Returns < 0 if main_str from position offset is less than str, > 0 if it is greater than str, and 0 if they are equal. If offset is equal to or greater than the length of main_str, or the length is set and is less than 1 (prior to PHP 5.6), substr_compare() prints a warning and returns FALSE.

Changelog:

5.6.0

length 0

5.1.0

Added the possibility to use a negative offset.

Examples:

A substr_compare() example

<?php
echo substr_compare("abcde", "bc", 1, 2); // 0
echo substr_compare("abcde", "de", -2, 2); // 0
echo substr_compare("abcde", "bcg", 1, 2); // 0
echo substr_compare("abcde", "BC", 1, 2, true); // 0
echo substr_compare("abcde", "bc", 1, 3); // 1
echo substr_compare("abcde", "cd", 1, 2); // -1
echo substr_compare("abcde", "abc", 5, 1); // warning
?>