20.async和await(es7)

App.js

/** 
 *  async & await
 * 
 */

// async function myFunc(){
//   // return "Hello World!";

//   const promise = new Promise((resolve,reject) => {
//     setTimeout(() => resolve('Hello World!'),2000)
//   })

//   // 错误信息
//   const error = true;

//   if(!error){
//     // 等待resolve执行完毕之后,才会执行
//     const res = await promise;
//     return res;
//   }else{
//     await Promise.reject(new Error("error: 报错了!"));
//   }
// }

// // console.log(myFunc());

// myFunc()
//   .then(data => console.log(data))
//   .catch(err => console.log(err));

// 请求数据
async function getUsers(){
  const response = await fetch("http://jsonplaceholder.typicode.com/users");
  const data = await response.json();
  return data;
}

getUsers().then(users => console.log(users))

esay HTTP.JS

/**
 * 封装fetch
 * 更快,更简单的请求数据
 *
 * @version 1.0.0
 * @author  米斯特吴
 * @license MIT
 *
 **/

 class EasyHttp{
   // get 
   get(url){
     return new Promise((resolve,reject) => {
        fetch(url)
          .then(res => res.json())
          .then(data => resolve(data))
          .catch(err => reject(err))
     })
   }

   // post
   post(url,data){
    return new Promise((resolve,reject) => {
       fetch(url,{
         method:"POST",
         headers:{
           'Content-type':'application/json'
         },
         body:JSON.stringify(data)
       })
         .then(res => res.json())
         .then(data => resolve(data))
         .catch(err => reject(err))
    })
  }

  // put
  put(url,data){
    return new Promise((resolve,reject) => {
       fetch(url,{
         method:"PUT",
         headers:{
           'Content-type':'application/json'
         },
         body:JSON.stringify(data)
       })
         .then(res => res.json())
         .then(data => resolve(data))
         .catch(err => reject(err))
    })
  }

  // delete
  delete(url){
    return new Promise((resolve,reject) => {
       fetch(url,{
         method:"DELETE",
         headers:{
           'Content-type':'application/json'
         }
       })
         .then(res => res.json())
         .then(data => resolve('数据删除成功!'))
         .catch(err => reject(err))
    })
  }
 }