思考以下异步编程中的执行顺序和结果：
async function async1() {
console.log("async1 start");
await async2();
console.log("async1 end");
}
async function async2() {
setTimeout(() => {
console.log('timer')
}, 0)
console.log("async2");
}
async1();
console.log("start")
结果如下：
async1 start
async2
start
async1 end
timer
async function async1 () {
console.log('async1 start');
await new Promise(resolve => {
console.log('promise1')
resolve('promise resolve')
})
console.log('async1 success');
return 'async1 end'
}
console.log('srcipt start')
async1().then(res => {
console.log(res)
})
new Promise(resolve => {
console.log('promise2')
setTimeout(() => {
console.log('timer')
})
})
结果如下：
srcipt start
async1 start
promise1
promise2
async1 success
async1 end
timer
原创文章，作者：czhdawn，如若转载，请注明出处：https://www.czhdawn.cn/archives/4959
