async await
function 摇色子(){
return new Promise((resolve,reject)=>{
let sino=parseInt(Math.random()*6+1)
setTimeout(()=>{
resolve(sino)
},3000)
})
}
async function test(){
let n=await 摇色子()
console.log(n)
console.log(123)
}
test()
console.log(456)
![](https://img2020.cnblogs.com/blog/1019711/202004/1019711-20200409111825241-1546059223.png)
上面这段代码async中使await 摇色子()先执行,等到三秒后执行完再把得到的结果赋值给左边的n,也就是说test函数需要三秒钟才执行完成,所以test函数是异步的,因此前面必须写async