1 //獲取字符串字節長度
 2 String.prototype.charLen = function() {
 3     var self = this;
 4     if(""==self) return 0; 
 5     var l=0; 
 6     for(var i=0;i<self.length;i++) 
 7     { 
 8         if(self.charCodeAt(i)>255) l+=2; 
 9         else l++; 
10     } 
11     return l;
12 };
13 
14 //刪除字符串左邊空格
15 String.prototype.ltrim = function() {
16     var self = this;
17     if("" == self) return '';
18     return self.replace(/(^\s*)/g,"");
19 }
20 
21 //刪除字符串兩端空格
22 String.prototype.trim = function() {
23     var self = this;
24     if("" == self) return '';
25     return self.replace(/(^\s*)|(\s*$)/g, "");
26 };
27 
28 //刪除字符串右邊空格
29 String.prototype.ltrim = function() {
30     var self = this;
31     if("" == self) return '';
32     return self.replace(/(\s*$)/g,"");
33 }