什么是Javascript中的导出和原型？ [英] What is exports and prototype in Javascript?

问题描述

我是Javascript的新手，并且在我阅读的代码中看到了很多导出和原型的用法。它们主要用于什么以及它们如何工作？

I am new to Javascript and am seeing a lot of usage of exports and prototype in the code that I read. What are they mainly used for and how do they work?

//from express
var Server = exports = module.exports = function HTTPSServer(options, middleware){
  connect.HTTPSServer.call(this, options, []);
  this.init(middleware);
};

Server.prototype.__proto__ = connect.HTTPSServer.prototype;

推荐答案

导出用于使模块的某些部分可用于模块外部的脚本。所以当有人在另一个脚本中使用 require 时，如下所示：

Exports is used to make parts of your module available to scripts outside the module. So when someone uses require like below in another script:

var sys = require("sys");  

他们可以访问您在 module.exports中放置的任何函数或属性

在您的示例中理解原型的最简单方法是 Server 是一个继承的类 HTTPSServer 的所有方法。 prototype 是在javascript中实现类继承的一种方法。

The easiest way to understand prototype in your example is that Server is a class that inherits all of the methods of HTTPSServer. prototype is one way to achieve class inheritance in javascript.

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