(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.
haystack
The main string being compared.
needle
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 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
?>