# Modularity

You can extract some common code into a separate js file as a module. Modules can only expose their interfaces externally through module.exports or exports.

Notice: -exports is a reference to module.exports, so changing the direction of exports in the module at will will cause unknown errors. Therefore, it is recommended that developers use module.exports to expose module interfaces, unless you have a clear understanding of the relationship between the two. -Mini programs currently do not support the direct import of node_modules. When developers need to use node_modules, it is recommended to copy the relevant code to the directory of the mini program, or use the [npm](https://developers. weixin.qq.com/miniprogram/dev/devtools/npm.html) function.

// common.js
function sayHello(name) {
  console.log(`Hello little game framework!`)
}
function sayGoodbye(name) {
  console.log(`Goodbye game framework!`)
}

module.exports.sayHello = sayHello
exports.sayGoodbye = sayGoodbye

# File scope

Variables and functions declared in a JavaScript file are only valid in that file; variables and functions with the same name can be declared in different files without affecting each other.

# Global Object

Similar to the browser's Window and NodeJS's global, the mini game also has a global object GameGlobal. Variables can be passed in multiple files through GameGlobal.

// a.js

GameGlobal.globalData = 1

// b.js

console.log(GameGlobal.globalData) // output "1"