1、实现函数
function StringBuilder(args)
{
this._strings = [];
this._isBuild=false;//是否创建
this._string=""; //创建后的字符串
for(var i=0;i<arguments.length ;i++){
this._strings.push(arguments[0]);
}
}
StringBuilder.prototype.append = function(str)
{
this._strings.push(str);
this._isBuild=false ;
return this;
}
//这个实现不太好....
StringBuilder.prototype.appendFormat=function(template,args){
if(arguments.length == 2 && typeof (args) == "object"){
template =template.format(args);
}
else{
var params="";
for(var i=1;i<arguments.length ;i++){
params +='"'+arguments[i]+'"';
if(i!=arguments.length-1){
params +=",";
}
}
eval("template =template.format("+params+")");
}
this._strings.push(template);
this._isBuild=false;
return this;
}
StringBuilder.prototype.toString = function()
{
if(!this._isBuild){
this._string=this._strings.join("");
}
return this._string;
}
//返回长度
StringBuilder.prototype.length = function()
{
if(!this._isBuild){
this._string=this._strings.join("");
}
return this._string.length;
}
// 删除最后几个字符
StringBuilder.prototype.del = function(lastNum)
{
var len = this.length();
var str = this.toString();
this._string= str.slice(0,len-lastNum);
this._strings = [];
this._strings.push(this._string);
this.isBuild=true ;
return this ;
}
简单调用：
var sb= new StringBuilder();
sb.append("<div>");
sb.appendFormat("<span>{0}</span>","loogn");
sb.append("</div>");
var result=sb.toString ();
//result结果为：<div><span>loogn</span></div>
