Modules in ECMAScript

Create Modules

Create new Javascript files as below:

Create Module 1

Create new Javascript file named demo1.js. This file contains code demo as below:

var age = 123;
var fullName = 'ABC';
let price = 4.5;

module.exports = { age, fullName, price };

Create Module 2

Create new Javascript file named demo2.js. This file contains code demo as below:

function generateRandom() {
    return Math.random();
}

function sum(a, b) {
    return a + b;
}

module.exports = { generateRandom, sum }

Create Module 3

Create new Javascript file named demo3.js. This file contains code demo as below:

class Product {

    constructor(id, name, price, quantity) {
        this.id = id;
        this.name = name;
        this.price = price;
        this.quantity = quantity;
    }

    toString() {
        return 'Id: ' + this.id + '\nName: ' + this.name + '\nPrice: ' + this.price + '\nQuantity: ' + this.quantity;
    }

    total() {
        return this.price * this.quantity;
    }

}

module.exports = { Product }

Create Index File

Create new Javascript file named index.js. This file contains code demo as below:

let module1 = require('./module1.js');
let module2 = require('./module2.js');
let module3 = require('./module3.js');

console.log('Age: ' + module1.age);
console.log('Full Name: ' + module1.fullName);
console.log('Price: ' + module1.price);

console.log('Generate Random: ' + module2.generateRandom());
console.log('Sum: ' + module2.sum(1, 2));

let product = new module3.Product('p01', 'name 1', 5, 2);
console.log(product.toString());
console.log('Total: ' + product.total());

Output

Use node index.js statement run code demo

Age: 123
Full Name: ABC
Price: 4.5

Generate Random: 0.8066028429716401
Sum: 3

Id: p01
Name: name 1
Price: 5
Quantity: 2
Total: 10