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    strripos

    (PHP 5, PHP 7, PHP 8)

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

    Description

    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.

    Parameters

    haystack

    The string to search in.

    needle

    The string to search for.

    Prior to PHP 8.0.0, 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 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.

    Note:

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

    Return Values

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

    Warning

    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
    8.2.0 Case folding no longer depends on the locale set with setlocale(). Only ASCII case folding will be done. Non-ASCII bytes will be compared by their byte value.
    8.0.0 needle now accepts an empty string.
    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 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)";
    }
    ?>

    The above example will output:

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

    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
    • 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

    up
    5
    Yanik Lupien
    17 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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    0
    Anonymous
    14 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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    0
    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
    16 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
    17 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*/
    ?>
    up
    -1
    ElectroFox
    17 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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