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

Description

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.

Return Values

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 length is set and is less than 1, substr_compare() prints a warning and returns FALSE.

Changelog

Version	Description
5.1.0	Added the possibility to use a negative `offset`.

Examples

Example #1 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
?>