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);
}
}
?>
(PHP 5, PHP 7)
strripos — Find the position of the last occurrence of a case-insensitive substring in a 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.
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 lastoffset
bytes.
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.
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.
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.
|
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 ($pos)";
}
?>
Exemplul de mai sus va afișa:
Congratulations! We found the last (aB) in (ababcd) at position (2)
Simple way to implement this function in PHP 4
<?php
if (function_exists('strripos') == false) {
function strripos($haystack, $needle) {
return strlen($haystack) - strpos(strrev($haystack), $needle);
}
}
?>
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.
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 $pos;
}/* endfunction strripos */
}/* endfunction exists strripos */
?>
Suppose you just need a stripos function working backwards expecting that strripos does this job, you better use the following code of a custom function named strbipos:
<?php
function strbipos($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.
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 $pos;
}/* endfunction strripos*/
}/* endfunction exists strripos*/
?>
Sorry, I made that last post a bit prematurely. One more thing wrong with the simple php4 version is that it breaks if the string is not found. It should actually look like this:
<?php
if (function_exists('strripos') == false) {
function strripos($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.
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);