promise aync await timeout 执行顺序

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