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strripos

(PHP 5, PHP 7)

strripos — Find the position of the last occurrence of a case-insensitive substring in a string

Descrierea

strripos ( string $haystack , string $needle [, int $offset = 0 ] ) : int|false

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

Unlike the strrpos(), strripos() is case-insensitive.

Parametri

haystack

The string to search in.

needle

Dacă needle nu este un șir de caractere, el este transformat în întreg și aplicat ca valoarea ordinală a caracterului. Acest comportament este învechit începând cu PHP 7.3.0 și utilizarea lui este foarte nerecomandată. În dependență de comportamentul dorit needle trebuie transformat în mod explicit în șir de caractere, sau trebuie efectuat un apel explicit către chr().

offset

If zero or positive, the search is performed left to right skipping the first offset bytes of the haystack.

If negative, the search is performed right to left skipping the last offset bytes of the haystack and searching for the first occurrence of needle.

Notă:
This is effectively looking for the last occurrence of needle before the last offset bytes.

Valorile întoarse

Returns the position where the needle exists relative to the beginnning of the haystack string (independent of search direction or offset).

Notă: 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
8.0.0	Passing an int as `needle` is no longer supported.
7.3.0	Passing an int as `needle` has been deprecated.

Exemple

Example #1 A simple strripos() example


<?php
$haystack = 'ababcd';
$needle   = 'aB';

$pos      = strripos($haystack, $needle);

if ($pos === false) {
    echo "Sorry, we did not find ($needle) in ($haystack)";
} else {
    echo "Congratulations!\n";
    echo "We found the last ($needle) in ($haystack) at position ($pos)";
}
?>

Exemplul de mai sus va afișa:

   Congratulations!
   We found the last (aB) in (ababcd) at position (2)

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
strrpos() - Find the position of the last occurrence of a substring in a string
strrchr() - Find the last occurrence of a character in a string
stristr() - Case-insensitive strstr
substr() - Return part of a string

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User Contributed Notes 7 notes

down

Yanik Lupien ¶

16 years ago


Simple way to implement this function in PHP 4

<?php
if (function_exists('strripos') == false) {
    function strripos($haystack, $needle) {
        return strlen($haystack) - strpos(strrev($haystack), $needle);
    }
}

?>

down

Anonymous ¶

13 years ago


Generally speaking, linear searches are from start to end, not end to start - which makes sense from a human perspective. If you need to find strings in a string backwards, reverse your haystack and needle rather than manually chopping it up.

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peev[dot]alexander at gmail dot com ¶

16 years ago


OK, I guess this will be the final function implementation for PHP 4.x versions ( my previous posts are invalid )

<?php

if(!function_exists("stripos")){
    function stripos(  $str, $needle, $offset = 0  ){
        return strpos(  strtolower( $str ), strtolower( $needle ), $offset  );
    }/* endfunction stripos */
}/* endfunction exists stripos */

if(!function_exists("strripos")){
    function strripos(  $haystack, $needle, $offset = 0  ) {
        if(  !is_string( $needle )  )$needle = chr(  intval( $needle )  );
        if(  $offset < 0  ){
            $temp_cut = strrev(  substr( $haystack, 0, abs($offset) )  );
        }
        else{
            $temp_cut = strrev(    substr(   $haystack, 0, max(  ( strlen($haystack) - $offset ), 0  )   )    );
        }
        if(   (  $found = stripos( $temp_cut, strrev($needle) )  ) === FALSE   )return FALSE;
        $pos = (   strlen(  $haystack  ) - (  $found + $offset + strlen( $needle )  )   );
        return $pos;
    }/* endfunction strripos */
}/* endfunction exists strripos */
?>

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-1

dimmav at in dot gr ¶

15 years ago


Suppose you just need a stripos function working backwards expecting that strripos does this job, you better use the following code of a custom function named strbipos:

<?php
function strbipos($haystack="", $needle="", $offset=0) {
// Search backwards in $haystack for $needle starting from $offset and return the position found or false

    $len = strlen($haystack);
    $pos = stripos(strrev($haystack), strrev($needle), $len - $offset - 1);
    return ( ($pos === false) ? false : $len - strlen($needle) - $pos );
}

// Test
$body = "01234Xy7890XYz456xy90";
$str = "xY";
$len = strlen($body);
echo "TEST POSITIVE offset VALUES IN strbipos<br>";
for ($i = 0; $i < $len; $i++) {
    echo "Search in [$body] for [$str] starting from offset [$i]: [" . strbipos($body, $str, $i) . "]<br>";
}
?>

Note that this function does exactly what it says and its results are different comparing to PHP 5 strripos function.

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-1

peev[dot]alexander at gmail dot com ¶

16 years ago


I think you shouldn't underestimate the length of $needle in the search of THE FIRST POSITION of it's last occurrence in the string. I improved the posted function, with added support for offset. I think this is an exact copy of the real function:

<?php
if(!function_exists("strripos")){
    function strripos($haystack, $needle, $offset=0) {
        if($offset<0){
            $temp_cut = strrev(  substr( $haystack, 0, abs($offset) )  );
        }
        else{
            $temp_cut = strrev(  substr( $haystack, $offset )  );
        }
        $pos = strlen($haystack) - (strpos($temp_cut, strrev($needle)) + $offset + strlen($needle));
        if ($pos == strlen($haystack)) { $pos = 0; }
        return $pos;
    }/* endfunction strripos*/
}/* endfunction exists strripos*/
?>

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-1

ElectroFox ¶

16 years ago


Sorry, I made that last post a bit prematurely.  One more thing wrong with the simple php4 version is that it breaks if the string is not found.  It should actually look like this:

<?php
if (function_exists('strripos') == false) {
    function strripos($haystack, $needle) {
        $pos = strlen($haystack) - strpos(strrev($haystack), strrev($needle));
        if ($pos == strlen($haystack)) { $pos = 0; }
        return $pos;
    }
}
?>

Note, we now check to see if the $needle was found, and if it isn't, we return 0.

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-7

admin at e-xxi dot net ¶

14 years ago


strripos() has very strange behaviour when you provide search position. For some reason it searches forward from the given position, instead of searching backward, that is more logical. 

For example if you want to find instanse of $what, previous to the last, strripos($where, $what, $last_what_pos-1) will not wark as expected. It will return $last_what_pos again and again. And that has no sence at all.

To prevent this, I just used $prev_last_what_pos = strripos(substr($where,0,$last_what_pos), $what);

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