PHP函数详细辨析之rtrim函数 By ACReaper

PHP函数详细剖析之rtrim函数 By ACReaper

string rtrim (string $str [, string $charlist ] )

这个函数很好理解、r表示右边、trim表示修剪、即右边修剪、默认修剪字符str右边的字符。默认修剪空格字符。

而当指定$charlist时、其修剪方法是一个个字符的匹配。

先从$charlist取第一个字符和$str最后一个匹配、如果匹配则删除$str后面那个字符。

不匹配则接着匹配$charlist的下个字符直到、$charlist被扫描一篇且没有匹配则完成右裁剪。

如果有匹配的则从$charlist的头开始重新和新的$str的尾字符一个个匹配。

例子：

<?php // Example 1:   rtrim('This is a short short sentence', 'short sentence');   // returns 'This is a'   // If you were expecting the result to be 'This is a short ',   // then you're wrong; the exact string, 'short sentence',   // isn't matched.  Remember, character-by-character comparison!   // Example 2:   rtrim('This is a short short sentence', 'cents');   // returns 'This is a short short '?> 

2013 09 11

By ACReaper