异步async

let p1 = new Promise((resolve,reject)=>{

  //模拟异步1

setTimeout(()=>{

  //  console.log('异步1')

  resolve("异步1");

},3500);

})

let p2 = new Promise((resolve,reject)=>{

   //模拟异步2

setTimeout(()=>{

  //   console.log('异步2')

  resolve("异步2");

},800);

})

let p3 = new Promise((resolve,reject)=>{

   //模拟异步3

setTimeout(()=>{

  //   console.log('异步3')

  resolve("异步3")

},1500);

})

 

async

let as = async ()=>{
  let r1 = await p1;
  let r2 = await p2;
  let r3 = await p3;
  console.log(r1);
  console.log(r2);
  console.log(r3);
}
as();


合并数组输出

// let as = async()=>{

//   let all = [await p1,await p2,await p3];

//   console.log(all);

// }

// as();

其他输出方法

async function as(){
  let result = await p2
 return  result ;
}
as().then(value=>{
  console.log(value)
})