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')
},0)
async1();
new Promise(function(resolve){
console.log('promise1')
resolve();
}).then(function(){
console.log('promise2')
})
console.log('script end')
script start
async1 start
async2
promise1
script end
promise2
async1 end
setTimeout
顺序:1.同步的 谁在前先执行谁 2.异步的 then > await之后 > timeout