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 - Manual: strripos
2024-11-15
strripos
(PHP 5, PHP 7, PHP 8)
strripos — 计算指定字符串在目标字符串中最后一次出现的位置（不区分大小写）
说明
strripos(string
$haystack, string $needle, int $offset = 0): int以不区分大小写的方式查找指定字符串在目标字符串中最后一次出现的位置。与 strrpos() 不同，strripos() 不区分大小写。
参数
-
haystack -
在此字符串中进行查找。
-
needle -
注意
needle可以是一个单字符或者多字符的字符串。 -
offset -
参数
offset可以被指定来查找字符串中任意长度的子字符串。负数偏移量将使得查找从字符串的起始位置开始，到
offset位置为止。
返回值
返回 needle 相对于 haystack 字符串的位置(和搜索的方向和偏移量无关)。同时注意字符串的起始位置为 0 而非 1。
如果 needle 未被发现，返回 false。
范例
示例 #1 strripos() 简单范例
<?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)";
}
?>
以上例程会输出：
Congratulations! We found the last (aB) in (ababcd) at position (2)
add a note
User Contributed Notes 7 notes
Yanik Lupien ¶
14 years ago
Anonymous ¶
11 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.
peev[dot]alexander at gmail dot com ¶
14 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 $pos;
}/* endfunction strripos */
}/* endfunction exists strripos */
?>
dimmav at in dot gr ¶
13 years ago
Suppose you just need a stripos function working backwards expecting that strripos does this job, you better use the following code of a custom function named strbipos:
<?php
function strbipos($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.
peev[dot]alexander at gmail dot com ¶
14 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 $pos;
}/* endfunction strripos*/
}/* endfunction exists strripos*/
?>
ElectroFox ¶
14 years ago
Sorry, I made that last post a bit prematurely. One more thing wrong with the simple php4 version is that it breaks if the string is not found. It should actually look like this:
<?php
if (function_exists('strripos') == false) {
function strripos($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.
admin at e-xxi dot net ¶
12 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);
IT
PHP
编程语言
Linux
开发编程
科技
Elasticsearch
HTML/CSS/XML
网络
JAVA
NoSQL
数据库
面试
C/C++
Golang
Git
算法
操作系统
正则表达式
Redis
互联网
MySql
JavaScript
运维
软件
国际
架构设计
Mac OS
TCP/IP
Excel
Vim
Windows
Socket
Oracle
VR
MongoDB
Python
运营
MemCache
商业
硬件
电子
娱乐
设计
nginx
摄影
游戏
WordPress
HTTP
团建
数码电器
广告
--
php7 安装fileinfo扩展
preg_split — 通过一个正则表达式分隔字符串
php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题
[PHP] inet_pton/inet_ntop IP地址转换函数
array_multisort() 多字段排序
PHPMailer设置utf8 PHPMailer字符集CharSet
ADORecordSet对象
adodb手册
PHP 8.1
[鸟哥]PHP_INT_MIN 和 -9223372036854775808
opcache预加载
Composer的Packagist资源
mysql面试题
[鸟哥]PHP FFI详解 - 一种全新的PHP扩展方式
PHP7添加redis扩展
PHP mkdir()写出来的权限与mode值不符合
Packagist / Composer 中国全量镜像
php中几种注释规范
利用php soap实现web service
PHP获取指定函数定义在哪个文件中及行号