In-depth understanding of the concepts and usage of commonJS

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##Common Understanding of .js!

commonJS specification:

1. The file is the module

Each file is a scope, and the variables\functions defined in the file are Private,

is invisible to other modules;

2. Use module.exports (exports) to expose external interfaces.

The module variable represents the current module, Module is an object. Use the exports attribute of this object to expose the external interface;

3. Use require to load dependent modules synchronously

For example:

---

a. js: This is an immediately executed function expression to expose the interface

var moduleA = (function () {
var aFlag = false;
function keepMoving () {
}
b = 1;
// 只暴露keepMoving 方法
return {
keepMoving: keepMoving
};
})()

---

a.js The code of function module a

var aFlag = false;
function keepMoving () {
}
b = 1;
module.exports = {//使用 module.exports 暴露接口
keepMoving: keepMoving
};

---

d.js This module depends on the above Module A

//使用require加载模块A;
var moduleA = require('./a.js');
function methodD() {//调用模块a里面的方法
moduleA.keepMoving();
}
//暴露模块D的接口
module.exports = {
methodD: methodD
};

Related recommendations:

First introduction to commonjs

Brief understanding of CommonJS specifications

##javascript modularization of CommonJS, AMD, CMD, UMD, ES6

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