strrchr()

(PHP 4, PHP 5, PHP 7)

查找指定字符在字符串中的最后一次出现

说明

该函数返回$haystack字符串中的一部分，这部分以$needle的最后出现位置开始，直到$haystack末尾。

参数

在该字符串中查找。

如果$needle包含了不止一个字符，那么仅使用第一个字符。该行为不同于strstr()。

如果$needle不是一个字符串，那么将被转化为整型并被视为字符顺序值。

返回值

该函数返回字符串的一部分。如果$needle未被找到，返回FALSE。

更新日志

范例

Example #1strrchr()范例

注释

Note:此函数可安全用于二进制对象。

参见

• strstr()查找字符串的首次出现
• strrpos()计算指定字符串在目标字符串中最后一次出现的位置

To extract your portion of a string without the actual character you searched for, you can use:

just a small addition to carlos dot lage at gmail dot com note which makes it a bit more useful and flexible:

to: repley at freemail dot it
the code works very well, but as i was trying to cut script names (e.g.: $_SERVER["SCRIPT_NAME"] => /index.php, cut the string at "/" and return "index.php") it returned nothing (false). i've modified your code and now it works also if the needle is the first char.
- regards from germany

$filename = 'strrchr_test.php';
print strrchr( $filename, '.' );
Result:
.php
$other_filename = 'strrchr_test.asp.php';
print strrchr( $other_filename, '.' );
Result:
.php

The function provided by marcokonopacki at hotmail dot com isn't really a reverse-version of strrchr(), rather a reverse version of strchr(). It returns everything from the start of $haystack up to the FIRST instance of the $needle. This is basically a reverse of the behavior which you expect from strchr(). A reverse version of strrchr() would return everything in $haystack up to the LAST instance of $needle, eg:

Note that this function will need to be modified slightly to work with pre 4.0b3 versions of PHP due to the return type of strrpos() ('0' is not necessarily 'false'). Check the documentation on strrpos() for more info. 
A function like this can be useful for extracting the path to a script, for example:

to marcokonopacki at hotmail dot com.
I had to make a slight change in your function for it to return the complete needle inclusive.
// Reverse search of strrchr.
function strrrchr($haystack,$needle)
{
  // Returns everything before $needle (inclusive).
  //return substr($haystack,0,strpos($haystack,$needle)+1);
  // becomes
  return substr($haystack,0,strpos($haystack,$needle)+strlen($needle));
}
Note: the +1 becomes +strlen($needle)
Otherwise it only returns the first character in needle backwards.

strrchr is also very useful for finding the extension of a file. For example:
$ext = strrchr($filename, ".");
and $ext will contain the extension of the file, including a ".", if the file has an extension, and FALSE if the file has no extension. If the file has multiple extensions, such as "evilfile.jpg.vbs", then this construction will just return the last extension.

I used dchris1 at bigpond dot net dot au 's reverse strrchr and reduced it to one line of code and fixed it's functionality - the real strrchr() returns FALSE if the needle is not found, not the haystack :)

I think that a good way (I don't know if is the best one) to extract a portion from a string:

Is faster that substr(strrchr...

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