学习prototype有感

1,打上checkbox,实现对文本框中内容的格式化

function Chkbacksend()
        {
            var befvalue=document.getElementById("txtContent").value;
            if(document.getElementById("chkMustBack").checked)
            {
                document.getElementById("txtContent").value=befvalue.EndFlag().AddTip(true);
            }
            else
            {
                document.getElementById("txtContent").value=befvalue.EndFlag().AddTip(false);
            }
        }

2,prototype必须以标点结尾

String.prototype.EndFlag=function()
        {
            var pattern = /(\.|。|！|!|\?|？|,|，)$/;
            if(this.length>0)
            {
                if(pattern.test(this))
                {
                    return this
                }
                else
                {
                    return this+"。";
                }
            }
            return this;
        }

3,prototype添加特定的字符串

String.prototype.AddTip = function(flag)
        {
            var newcontents=this;
            if(flag)
            {
                if(!(this.indexOf("请回复!")>-1))
                {
                    newcontents=this+"请回复!";
                }
            }
            else
            {
                if(this.indexOf("请回复!")>-1)
                {
                    newcontents=this.replace("请回复!","");
                }
            }
            return newcontents;
        }

我的网摘中存放了个精彩的脚本代码优化的文章.借鉴的还很不到位!