promise async

<script type="text/javascript">
              //async await
    //返回Promise let timer = 
    async function timer() {
        return new Promise((reslove, reject) => {
//          setTimeout(() => {
                reslove('434str');
            //}, 1000);
        })
    }
    timer().then(result => {
        console.log(result);
    }).catch(err => {
        console.log(err.message);
    })

    //返回同步的值
    let sayHello = async function sayHello() {
        let hi = 'hello world'//等同于return Promise.resolve(hi);
        return hi
    }
    sayHello().then(res => {
        console.log(res)
    }).catch(err => {
        console.log(err.message);
    })
    
      //返回Promise 
   let timepro =  function timer() {
       // return new Promise((reslove, reject) => {
//          setTimeout(() => {
          //      reslove('434str');
            //}, 1000);
       // })
       return Promise.resolve('hi');
    }
    timepro().then(result => {
        console.log(result);
    }).catch(err => {
        console.log(err.message);
    })
        </script>