js基础-题目48

整理下之前做的有点疑惑的js基础题目和大家分享以下，如果大家觉得有用，别忘了点一下赞哦

async

async function t1(){
    
    //flag1
  let a = await "小刘"
  console.log(a)
}
async function t2(){
    
    
  let a = await new Promise(resolve =>{
    
    })
  console.log(a)
}
async function t3(){
    
    
  let a = await new Promise(resolve=>{
    
    resolve()})
  console.log(a)
}
async function t4(){
    
    
  let a = await new Promise(resolve=>{
    
    resolve("hello")})
  console.log(a)
}
async function t5(){
    
    
  let a = await new Promise(resolve=>{
    
    resolve("hello")})
    .then(()=>{
    
    return "xiaoniu"})
  console.log(a)
}
async function t6(){
    
     //flag6 
  let a = fn().then(res=>{
    
    return res})
  console.log(a)
}
async function fn(){
    
    
  await new Promise(resolve=>{
    
    resolve("joke")})
}

t1() // Promise { <pending> }
t2() // 小刘
t3() // undefined
t4() // hello
t5() // xiaoniu
t6() // Promise {<resolved>: undefined}

flag1处：await一个非promise对象，会返回Promise { <pending> }对象
flag6处：fn() 返回了一个promise<padding>对象 ,await 返回promse成功的回调，而这个 promise 并没有回调，所以promise状态变为了 <resolved>，而返回值时undefined。
这题我也没理解透彻