js字符串长度校验

//计算字符串长度包含中文
 function getByteLen(val) {
        var len = 0;
        for (var i = 0; i < val.length; i++) {
             var a = val.charAt(i);
             if (a.match(/[^\x00-\xff]/ig) != null)
            {
                len += 2;
            }
            else
            {
                len += 1;
            }
        }
        return len;
    }