promise 函数使用最佳实践体验

let checkLogin = function () {  return new Promise(function (resolve,reject) {    let flag = document.cookie.indexOf("userId")>-1?true:false;    if(flag=true){      resolve({        status:0,        result:true      })    }else{      reject("error");    }  })};let getUserInfo = ()=>{  return new Promise((resolve,reject)=>{    let userInfo = {      userId:"101"    }    resolve(userInfo);  });}checkLogin().then((res)=>{  if(res.status==0){    console.log("login success");    return getUserInfo();  }}).catch((error)=>{  console.log(`errrs:${error}`)}).then((res2)=>{  console.log(`userId:${res2.userId}`)});

//多个承诺函数一起执行Promise.all([checkLogin(),getUserInfo()]).then(([res1,res2])=>{  console.log(`result1:${res1.result},result2:${res2.userId}`)})