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strripos

(PHP 5)

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

Опис

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

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

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

Параметри

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.

Значення, що повертаються

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.

Увага

Ця функція може повертати як логічне FALSE, так і нелогічне значення, яке прирівнюється до FALSE. Детальніше про це описується в розділі Логічний тип даних (Booleans). Використовуйте оператор === щоб перевірити значення, яке повертає дана функція.

Приклади

Приклад #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)";
}
?>

Наведений вище приклад виведе:

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

Прогляньте Також

strpos() - Знаходить позицію першого входження підрядка в рядку
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);
    }
}

?>

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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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