strrpos
(PHP 4, PHP 5, PHP 7, PHP 8)
strrpos — Find the position of the last occurrence of a substring in a string
Description
$haystack, string $needle, int $offset = 0): int|false
Find the numeric position of the last occurrence of
needle in the haystack string.
Parameters
-
haystack -
The string to search in.
-
needle -
Prior to PHP 8.0.0, if
needleis not a string, it is converted to an integer and applied as the ordinal value of a character. This behavior is deprecated as of PHP 7.3.0, and relying on it is highly discouraged. Depending on the intended behavior, theneedleshould either be explicitly cast to string, or an explicit call to chr() should be performed. -
offset -
If zero or positive, the search is performed left to right skipping the first
offsetbytes of thehaystack.If negative, the search is performed right to left skipping the last
offsetbytes of thehaystackand searching for the first occurrence ofneedle.Note:
This is effectively looking for the last occurrence of
needlebefore the lastoffsetbytes.
Return Values
Returns the position where the needle exists relative to the beginning of
the haystack string (independent of search direction
or offset).
Note: String positions start at 0, and not 1.
Returns false if the needle was not found.
This function may
return Boolean false, but may also return a non-Boolean value which
evaluates to false. Please read the section on Booleans for more
information. Use the ===
operator for testing the return value of this
function.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
Passing an int as needle is no longer supported.
|
| 7.3.0 |
Passing an int as needle has been deprecated.
|
Examples
Example #1 Checking if a needle is in the haystack
It is easy to mistake the return values for "character found at position 0" and "character not found". Here's how to detect the difference:
<?php
$pos = strrpos($mystring, "b");
if ($pos === false) { // note: three equal signs
// not found...
}
?>
Example #2 Searching with offsets
<?php
$foo = "0123456789a123456789b123456789c";
// Looking for '0' from the 0th byte (from the beginning)
var_dump(strrpos($foo, '0', 0));
// Looking for '0' from the 1st byte (after byte "0")
var_dump(strrpos($foo, '0', 1));
// Looking for '7' from the 21th byte (after byte 20)
var_dump(strrpos($foo, '7', 20));
// Looking for '7' from the 29th byte (after byte 28)
var_dump(strrpos($foo, '7', 28));
// Looking for '7' right to left from the 5th byte from the end
var_dump(strrpos($foo, '7', -5));
// Looking for 'c' right to left from the 2nd byte from the end
var_dump(strrpos($foo, 'c', -2));
// Looking for '9c' right to left from the 2nd byte from the end
var_dump(strrpos($foo, '9c', -2));
?>
The above example will output:
int(0) bool(false) int(27) bool(false) int(17) bool(false) int(29)
See Also
- strpos() - Find the position of the first occurrence of a substring in a string
- stripos() - Find the position of the first occurrence of a case-insensitive substring in a string
- strripos() - Find the position of the last occurrence of a case-insensitive substring in a string
- strrchr() - Find the last occurrence of a character in a string
- substr() - Return part of a string
