中英文时，占位符转换实体对象

String.prototype.format=function(){if(arguments.length===0)returnthis;varparam=arguments[0],str=this;if(typeof(param)==='object'){for(varkeyinparam)str=str.replace(newRegExp("\\{"+key+"\\}","g"),param[key]);returnstr;}else{for(vari=0;i<arguments.length;i++)str=str.replace(newRegExp("\\{"+i+"\\}","g"),arguments[i]);returnstr;}};var_obj={a:'1',b:'2'};varm="test{a}to{b}".format(_obj);