Javascript => 在节点 js 中是什么意思
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/39328295/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
What does => mean in node js
提问by deeveeABC
I am learning node js, and came across '=>' several times, however struggle to understand what this means.
我正在学习 node js，并=>多次遇到 ' '，但很难理解这意味着什么。
Here is an example:
下面是一个例子：
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
回答by roberrrt-s
It's nothing node-exclusive, it's an ES6 Arrow function expression
它不是节点专有的，它是一个ES6 箭头函数表达式
app.post('/add-item', (req, res) => {
// TODO: add an item to be posted
});
basically means:
基本上是指：
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 thisvalue.
这两个示例之间的主要区别在于，第一个示例在词法上绑定了this值。
回答by Vishal Gupta
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');
});
