js 箭头函数

 

1.箭头函数与function定义函数的写法：

 

 //function
function fn(a, b){
    return a + b;
}
//arrow function
var foo = (a, b)=>{ return a + b };

 

        var arrowfn = (a,b)=>{
            return a+b;
        }
        var res = arrowfn(2,3);
        console.log('箭头函数测试结果：' + res);

访问 https://blog.youkuaiyun.com/github_38851471/article/details/79446722 了解更多

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getJSON("/post/1.json").then(function(post) {
  return getJSON(post.commentURL);
}).then(function funcA(comments) {
  console.log("resolved: ", comments);
}, function funcB(err){
  console.log("rejected: ", err);
});

getJSON("/post/1.json").then(
  post => getJSON(post.commentURL)
).then(
  comments => console.log("resolved: ", comments),
  err => console.log("rejected: ", err)
);

getJSON("/post/1.json").then(function(post) {
  return getJSON(post.commentURL);
}).then(function funcA(comments) {
  console.log("resolved: ", comments);
}, function funcB(err){
  console.log("rejected: ", err);
});

getJSON("/post/1.json").then(
  post => getJSON(post.commentURL)
).then(
  comments => console.log("resolved: ", comments),
  err => console.log("rejected: ", err)
);