strrpos

(PHP 4, PHP 5, PHP 7)

strrposFind the position of the last occurrence of a substring in a string

Descrierea

strrpos ( string $haystack , mixed $needle [, int $offset = 0 ] ) : int

Find the numeric position of the last occurrence of needle in the haystack string.

Parametri

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. This behavior is deprecated as of PHP 7.3.0, and relying on it is highly discouraged. Depending on the intended behavior, the needle should either be explicitly cast to string, or an explicit call to chr() should be performed.

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.

Valorile întoarse

Returns the position where the needle exists relative to the beginning 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.

Avertizare

Această funcție poate întoarce valoarea Boolean FALSE, dar poate de asemenea întoarce o valoare non-Boolean care evaluează în FALSE. Vă rugăm să citiți secțiunea despre tipul Boolean pentru informații suplimentare. Utilizați operatorul === pentru a verifica valoarea întoarsă de această funcție.

Istoricul schimbărilor

Versiune Descriere
5.0.0 The needle may now be a string of more than one character.

Exemple

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)
?>

A se vedea și

  • 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