Node.js调用功能

Question

Is it possible to call a function in a Node.js module when it's required.

app.js

const Database = require('./database').Database;

const UsersModel = require('./model').Model; // pass the name = Users and database
const AdminsModel = require('./model').Model; // pass the name = Admins and database

database.js

export class Database {
    // some functions here
}

model.js

export class Model {
    onModelCreated(name, database) {
        this.name = name;
        this.database = database;
    }

    insert() {}
    find() {}
    delete() {}
    update() {}
}

Answer 1

Since require calls are cached, all the code inside the module is called once, when you require that module.

abc/index.js

const calledOnce = () => console.log('once');

calledOnce();

console.log('Also once');

module.exports = {
    ...
}