面试题（同步，异步）

```

// 今日头条面试题

async function async1() {

    console.log('async1 start')

    await async2()

    console.log('async1 end')

}

async function async2() {

    console.log('async2')

}

console.log('script start')

setTimeout(function () {

    console.log('settimeout')

})

async1()

new Promise(function (resolve) {

    console.log('promise1')

    resolve()

}).then(function () {

    console.log('promise2')

})

console.log('script end')

//答案：

script start

async1 start

async2

promise1

script end

async1 end

promise2

settimeout

```