JavaScript 扩展方法 trim 去除指定字符串

JavaScript中用于去除字符串中的空白字符的扩展方法【参考自:http://www.cnblogs.com/clyde/archive/2011/01/15/1936378.html】

 1 String.prototype.trim = function(pos)
 2 {
 3     var trimRegex;
 4     if (!pos)
 5     {
 6         pos = "g"; //
 7     }
 8     switch (pos.toLowerCase())
 9     {
10         case "l":
11             trimRegex = /^\s*/g;
12             break;
13         case "m":
14             trimRegex = /\b\s*/g; //有汉字时无效
15             break;
16         case "r":
17             trimRegex = /\s*$/g;
18             break;
19         case "b":
20             trimRegex = /(^\s*)|(\s*$)/g;
21             break;
22         case "g":
23             trimRegex = /\s/g;
24             break;
25         default: //默认去除全部的空白字符
26             trimRegex = /\s/g;
27             break;
28     }
29     return this.replace(trimRegex, "");
30 }