(PHP 4, PHP 5)
strrpos — Find the position of the last occurrence of a substring in a string
$haystack
, string $needle
[, int $offset = 0
] )
Find the numeric position of the last occurrence of
needle in the haystack string.
haystack
The string to search in.
needle
If needle is not a string, it is converted
to an integer and applied as the ordinal value of a character.
offset
If specified, search will start this number of characters counted from the beginning of the string. If the value is negative, search will instead start from that many characters from the end of the string, searching backwards.
Returns the position where the needle exists relative to the beginnning of
the haystack string (independent of search direction
or offset).
Also note that string positions start at 0, and not 1.
Returns FALSE if the needle was not found.
Această funcție poate întoarce valoarea Boolean FALSE, dar poate de
asemenea întoarce o valoare non-Boolean care evaluează în FALSE, cum ar fi
0 sau "". Vă rugăm să citiți secțiunea despre
tipul Boolean pentru mai multe
informații. Utilizați
operatorul === pentru a
verifica valoarea întoarsă de această funcție.
| Versiunea | Descriere |
|---|---|
| 5.0.0 |
The needle may now be a string of more than one
character.
|
| 5.0.0 |
The offset parameter was introduced.
|
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
$foo = "0123456789a123456789b123456789c";
var_dump(strrpos($foo, '7', -5)); // Starts looking backwards five positions
// from the end. Result: int(17)
var_dump(strrpos($foo, '7', 20)); // Starts searching 20 positions into the
// string. Result: int(27)
var_dump(strrpos($foo, '7', 28)); // Result: bool(false)
?>