分别去字符串前后，左边，右边空格
复制代码 代码如下:
String.prototype.trim=function(){returnthis.replace(/^\s+|\s+$/g,"")}
String.prototype.ltrim=function(){returnthis.replace(/^\s+/g,"")}
String.prototype.rtrim=function(){returnthis.replace(/\s+$/g,"")}