(PHP 5, PHP 7, PHP 8)
substr_compare — Binary safe comparison of two strings from an offset, up to length characters
$haystack,$needle,$offset,$length = null,$case_insensitive = false
substr_compare() compares haystack
from position offset with needle
up to length characters.
haystackThe main string being compared.
needleThe secondary string being compared.
offsetThe 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 needle compared to the length of
haystack minus the
offset.
case_insensitive
If case_insensitive is true, comparison is
case insensitive.
Returns -1 if haystack from position
offset is less than needle, 1
if it is greater than needle, and 0 if they are equal.
If offset is equal to (prior to PHP 7.2.18, 7.3.5) or
greater than the length of haystack, or the
length is set and is less than 0,
substr_compare() prints a warning and returns
false.
| Version | Description |
|---|---|
| 8.2.0 |
This function now returns -1 or 1,
where it previously returned a negative or positive number.
|
| 8.0.0 |
length is nullable now.
|
| 7.2.18, 7.3.5 |
offset may now be equal to the length of haystack.
|
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
?>