Java OOP-Java OOP Mentorship

Example

class BankAccount { private double balance; public double getBalance() { return balance; } public void deposit(double amount) { balance += amount; } }

Scenario

Encapsulation hides the internal state of an object and requires all interaction to be performed through an object's methods, increasing security and reducing system complexity. In a banking application, encapsulation prevents direct access to the balance of a bank account, ensuring it can only be modified through defined methods like deposit().

Example

class Employee { private String name; private String ID; public void work() {} } class Manager extends Employee { private int teamSize; public void manage() {} }

Scenario

Inheritance allows new classes to inherit properties and methods from existing classes. In a corporate management system, a 'Manager' class can inherit from an 'Employee' class, adding additional functionalities specific to managers, such as managing a team, while reusing existing code from the 'Employee' class.

Example

interface Shape { double calculateArea(); } class Circle implements Shape { private double radius; public double calculateArea() { return Math.PI * radius * radius; } } class Rectangle implements Shape { private double width, height; public double calculateArea() { return width * height; } }

Scenario

Polymorphism allows classes to be treated through interfaces they implement, enabling multiple forms of behaviors. In a graphic design application, different shapes like circles and rectangles can be manipulated uniformly using the Shape interface, allowing the application to support new types of shapes without altering existing code.

Example

abstract class Device { abstract void turnOn(); } class Smartphone extends Device { void turnOn() { System.out.println('Smartphone turning on...'); } }

Scenario

Abstraction allows you to define template classes that must be inherited to be utilized, ensuring certain methods are implemented. In an electronics control system, defining a Device class as abstract ensures that each specific device, like a Smartphone or Laptop, implements a turnOn method, providing specific behaviors for turning on each device.