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- What's the meaning of “=>” (an arrow formed from equals & greater than) in JavaScript? 10 answers
JavaScript中“=>”(由等于和大于等于的箭头形成)的含义是什么? 10个答案
I am learning node js, and came across '=>' several times, however struggle to understand what this means.
我正在学习节点js,并多次遇到'=>',但是很难理解这意味着什么。
Here is an example:
这是一个例子:
app.post('/add-item', (req, res) => {
// TODO: add an item to be posted
});
Do we actually need this in the above example? A simple explanation would be helpful. Thanks
在上面的例子中我们真的需要这个吗?一个简单的解释会有所帮助。谢谢
2 个解决方案
#1
22
It's nothing node-exclusive, it's an ES6 Arrow function expression
它不是节点独有的,它是ES6 Arrow函数表达式
app.post('/add-item', (req, res) => {
// TODO: add an item to be posted
});
basically means:
app.post('/add-item', function(req, res) {
// TODO: add an item to be posted
});
The main difference between these two examples is that the first one lexically binds the this value.
这两个例子的主要区别在于第一个例子是词汇上绑定了这个值。
#2
1
This is just a different way of writing an anonymous function:
这只是编写匿名函数的另一种方式:
$(document).ready(() => {
console.log('Hello I am typescript');
});
is equivalent to JavaScript:
相当于JavaScript:
$(document).ready(function(){
console.log('Hello I am typescript');
});
#1
22
It's nothing node-exclusive, it's an ES6 Arrow function expression
它不是节点独有的,它是ES6 Arrow函数表达式
app.post('/add-item', (req, res) => {
// TODO: add an item to be posted
});
basically means:
app.post('/add-item', function(req, res) {
// TODO: add an item to be posted
});
The main difference between these two examples is that the first one lexically binds the this value.
这两个例子的主要区别在于第一个例子是词汇上绑定了这个值。
#2
1
This is just a different way of writing an anonymous function:
这只是编写匿名函数的另一种方式:
$(document).ready(() => {
console.log('Hello I am typescript');
});
is equivalent to JavaScript:
相当于JavaScript:
$(document).ready(function(){
console.log('Hello I am typescript');
});