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: