闲着无聊，写一个小JS看看效果怎么样，结果让我大吃一惊。


var res1,res2;
function badfunction(){
var starDate = new Date();
var str = "";
for(var i=0;i<10000;i++){ str += i.toString; } res1 = str; return new Date()- starDate; } function batterfunction(){ var starDate = new Date(); var str = ""; var strRes = new Array(); for(var i=0;i<10000;i++){ strRes.push(i.toString); } str = strRes.join(""); res2 = str; return new Date()- starDate; } window.onload = function(){ document.write(badfunction()+"
");
document.write(batterfunction()+"
");
alert(res1===res2); //判断方法一于方法2结果是否一致。
}