promise和setTimeout async/await顺序面试题

async function async1(){
    console.log('async1 start')//2
    await async2() //await后面都作为回调内容 微任务1=>放在微任务队列
    console.log('async1 end') 
}
async function async2() {
    console.log('async2')//3
}
console.log('script start')//1

setTimeout(() => { //宏任务 setTimeout =>callback queue
    console.log('setTimeout')
});

async1()//

//初始化Promise是，传入的函数会立刻被执行
new Promise((resolve=>{
    console.log('promise1')//4
    resolve()
})).then(function () { //微任务2=>放在微任务队列
    console.log('promise2')
})
console.log('script end')//5

结果：

script start.
async1 start.
async2.
promise1.
script end
//同步代码执行完毕 call stack被清空----
//开始执行微任务----
async1 end.
promise2.
//(尝试出触发DOM渲染)
触发Event Loop ,执行宏任务------
setTimeout