fetch("服务器地址")

  .then(function(response) {

    //将获取到的数据使用 json 转换对象

    return response.json();

  })

  .then(function(data) {

    //获取转换后的格式

    console.log(data);

  })

  //如果有异常会在 catch 捕获

  .catch(function(e) {

    console.log("error");

  }); 

//实例化 request 对象
var myRequest = new Request(url, Option);

fetch(myRequest)
  .then(function(response) {
    console.log(response);
  })
  //如果有异常会在 catch 捕获
  .catch(function(e) {
    console.log("error");
  }); 

method = GET / POST / PUT / DELETE / HEAD 

let headers = new Headers({

  'Content-Type': 'text/plain'

}); 

var request = new Request("url", {

    headers: new Headers({

      "Content-Type": "text/plain"

    }),

    method : "POST",

    mode: "cors",

    redirect : "follow"

  });

fetch(request)

  .then((response) => {

    console.log(response);

  })

  .catch((error)=>{

    console.log(error);

  }); 

fetch(url)

  .then((response) => {

    //返回 object 类型

    return response.json();

  })

  .then((result) => {

    console.log(result);

  }); 

fetch(url)

  .then((response) => {

    //返回 string 类型

    return response.text();

  })

  .then((result) => {

    console.log(result);

  });　　 

var request = new Request("xx.img", {

    headers: new Headers({

      "Content-Type": "image/jpeg"

    }),

    method : "get",

    cache: 'default'

  });

fetch(request)

  .then((response) => {

    return response.blob();

  })

  .then((stories)=>{

    var objectURL = URL.createObjectURL(stories);

    let img = document.createElement("img");

    img.src = objectURL;

    document.querySelector("body").appendChild(img);

  });