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Balance as Private Field

Part of the Object Oriented Programming section of Coddy's JavaScript journey. Lesson 23 of 56.

Challenge

Let's make the BankAccount class more secure by converting the balance to a private field."

Your task:

Add #balance at the top of the class
Change this.balance to this.#balance in the constructor
Change this.balance to this.#balance in all methods

Try it yourself

import { BankAccount } from './bankAccount.js';

// Test the implementation
const testAccount = new BankAccount('Alex Johnson', 500);

console.log(testAccount.getAccountInfo()); // "Alex Johnson: $500"
console.log('Balance:', testAccount.getBalance()); // still works: 500
console.log('Balance:', testAccount.balance); // undefined

All lessons in Object Oriented Programming

1Objects & The this Keyword

Quick Review: Objects Adding Methods to Objects Understanding the this Keyword Constructor Functions The new Keyword Recap Challenge

4Methods & Managing State

Methods that modify state Method chaining pattern

7 Inheritance & The extends Key

Inheritance The "is-a" Relationship The extends Keyword The super() Method Inheriting Properties&Methods Recap Challenge

10Polymorphism

What is Polymorphism?Overriding Inherited Methods Using super Recap Challenge

13Composition vs. Inheritance

The "has-a" vs. "is-a"The Limits of Deep Inheritance Building objects

2Organizing Code

What are Modules?Exporting with export Importing with import Default vs. Named Exports

5Encapsulation & Access

Encapsulation Public & Private Class Fields Private Methods Recap Challenge

8Organizing OOP Code

Organize Classes into Modules

11Project: A Shape Renderer

Setup: Shape Class & Export Circle Class Inheritance Overriding & Area Method Static Shape Counter

14Library Management System

Designing the Library Book Class with Composition Book Author Validation

3Classes & Objects

What is a Class?Creating Instances Properties and Methods Recap Challenge

6Project: A Simple Bank Account

BankAccount Class Deposits and WithdrawalsBalance as Private Field

9Static Methods & Properties

Class-Level vs. Instance-Level Static Properties Static Utility Methods Recap challenge

12Getters & Setters

The get and set Keywords Computed Properties Validation and Side Effects Recap Challenge

15 Final Challenges

Game Character Builder E-commerce Product System University Management System Smart Home Device System

Practice on your own: Online JavaScript compiler