记录一下工作中的零碎收获
promise是javascript引擎内如任务,settime属于浏览器的API所以优先执行primise;
var r = new Promise(function(resolve, reject){
console.log("a");
resolve()
});
setTimeout(()=>console.log("d"), 0)
r.then(() => console.log("c"));
console.log("b")