随着时间后台数值添加的问题

var thisNum;//定义
var timeArray=[5,10,20];//定义随机时间数组
var timeT=timeArray[Math.round(Math.random()*2)]*60*1000;//随机取出一个值赋值给timeT
function addNum(){
if(window.localStorage.getItem('thisNum')!=''){
thisNum=window.localStorage.getItem('thisNum');//获取本地的数据
}else{
thisNum=100;
}
thisNum+=1;
window.localStorage.setItem('thisNum',thisNum);//设置本地的数据
console.log(window.localStorage.getItem('thisNum'));
setTimeout(addNum(),timeT);
timeT=timeArray[Math.round(Math.random()*2)]*60*1000;
}
window.onload=addNum();