最佳的前端监听事件触发方式

for (;;){
 var start = new Date().getTime();
  var newdate;
  while (true) {
    newdate=new Date().getTime();
    if (newdate - start > 4000) {
      start=newdate;
      this.$log.log("66666661");
      continue;
    }
  }
}

for (;;){
  var start = new Date().getTime();
  //  console.log('休眠前：' + start);
  var newdate;
  while (true) {
    newdate=new Date().getTime();
    if (newdate - start > 2000) {
      start=newdate;
      this.addChead();
      continue;
    }
  }
}