PHP4用户手册:函数->trim
trim
(PHP 3, PHP 4 >= 4.0.0)
trim -- 去除一个字符串开始和结尾的空白
描述
string trim (string str [, string charlist])
注意：第二个参数用在PHP 4.1.0
这个函数返回str字符串被去除首尾空白后的新字符串。不带第二个参数trim() 将去除下列字符：
" " (ASCII 32 (0x20)), 空格；
"\t" (ASCII 9 (0x09)), 制表符；
"\n" (ASCII 10 (0x0A)), 换行符；
"\r" (ASCII 13 (0x0D)), 回车符；
"\0" (ASCII 0 (0x00)), 空字符；
"\x0B" (ASCII 11 (0x0B)), 垂直制表符。
你可以通过charlist参数指定你想去除的字符。Simply list all characters that you want to be stripped. With .. you can specify a range of characters.
例1. trim()例子
<?php
$text = "\t\tThese are a few words :) ... ";
$trimmed = trim($text);
// $trimmed = "These are a few words :) ..."
$trimmed = trim($text," \t.");
// $trimmed = "These are a few words :)"
$clean = trim($binary,"\0x00..\0x1F");
// trim the ASCII control characters at the beginning and end of $binary
// (from 0 to 31 inclusive)
?>