Inheritance is one of the most important concepts in Object-Oriented Programming (OOP). It allows one class to reuse the properties and behaviors of another class. This helps in writing clean, reusable, and easy-to-maintain code.

What is Inheritance?

Inheritance is a mechanism where one class acquires the properties (variables) and behaviors (methods) of another class.

The class that provides features is called the Base Class (Parent Class)

The class that receives features is called the Subclass (Child Class)

👉 Inheritance represents an “IS-A” relationship

Example:

A Car is a Vehicle

Base Class (Parent Class)

The base class is the class whose properties and methods are inherited by another class.

Example:

Copy code

Java

class Vehicle {

int speed = 60;

void showSpeed() {

System.out.println(“Speed: “ + speed);

}

}

Here, Vehicle is the base class.

Subclass (Child Class)

The subclass is the class that inherits from the base class using keywords like:

extends (Java)

: (Python)

Example:

Copy code

Java

class Car extends Vehicle {

void showType() {

System.out.println(“This is a car”);

}

}

Here, Car is the subclass that inherits from Vehicle.

Object Creation in Inheritance

An object of the subclass can access members of:

Its own class

The base class

Copy code

Java

public class Main {

public static void main(String[] args) {

Car c = new Car();

c.showSpeed(); // from base class

c.showType(); // from subclass

}

}

Member Access Rules in Inheritance

Access to class members depends on access modifiers.

Common Access Modifiers:

public

protected

default

private

Access Rules Table (Java)

Access Modifier

Same Class

Same Package

Subclass

Outside Package

public

✔

✔

✔

✔

protected

✔

✔

✔

❌

default

✔

✔

❌

❌

private

✔

❌

❌

❌

Example with Access Modifiers:

Copy code

Java

class Parent {

public int a = 10;

protected int b = 20;

int c = 30; // default

private int d = 40;

}

Copy code

Java

class Child extends Parent {

void display() {

System.out.println(a); // allowed

System.out.println(b); // allowed

System.out.println(c); // allowed (same package)

// System.out.println(d); // NOT allowed

}

}

❌ Private members cannot be inherited.

Why Use Inheritance?

Inheritance provides many benefits:

✔ Code reusability

✔ Less duplication

✔ Easy maintenance

✔ Supports polymorphism

✔ Improves program structure

Real-World Example of Inheritance

Base Class: Employee

Subclass: Manager

A Manager is an Employee, but has extra responsibilities.

Conclusion

Inheritance helps classes share common behavior while allowing specialization. Understanding base classes, subclasses, and member access rules is essential for mastering OOP concepts and building real-world applications.vInheritance in Object-Oriented Programming (OOP)

Inheritance is one of the most important concepts in Object-Oriented Programming (OOP). It allows one class to reuse the properties and behaviors of another class. This helps in writing clean, reusable, and easy-to-maintain code.

What is Inheritance?

Inheritance is a mechanism where one class acquires the properties (variables) and behaviors (methods) of another class.

The class that provides features is called the Base Class (Parent Class)

The class that receives features is called the Subclass (Child Class)

👉 Inheritance represents an “IS-A” relationship

Example:

A Car is a Vehicle

Base Class (Parent Class)

The base class is the class whose properties and methods are inherited by another class.

Example:

Copy code

Java

class Vehicle {

int speed = 60;

void showSpeed() {

System.out.println(“Speed: “ + speed);

}

}

Here, Vehicle is the base class.

Subclass (Child Class)

The subclass is the class that inherits from the base class using keywords like:

extends (Java)

: (Python)

Example:

Copy code

Java

class Car extends Vehicle {

void showType() {

System.out.println(“This is a car”);

}

}

Here, Car is the subclass that inherits from Vehicle.

Object Creation in Inheritance

An object of the subclass can access members of:

Its own class

The base class

Copy code

Java

public class Main {

public static void main(String[] args) {

Car c = new Car();

c.showSpeed(); // from base class

c.showType(); // from subclass

}

}

Member Access Rules in Inheritance

Access to class members depends on access modifiers.

Common Access Modifiers:

public

protected

default

private

Access Rules Table (Java)

Access Modifier

Same Class

Same Package

Subclass

Outside Package

public

✔

✔

✔

✔

protected

✔

✔

✔

❌

default

✔

✔

❌

❌

private

✔

❌

❌

❌

Example with Access Modifiers:

Copy code

Java

class Parent {

public int a = 10;

protected int b = 20;

int c = 30; // default

private int d = 40;

}

Copy code

Java

class Child extends Parent {

void display() {

System.out.println(a); // allowed

System.out.println(b); // allowed

System.out.println(c); // allowed (same package)

// System.out.println(d); // NOT allowed

}

}

❌ Private members cannot be inherited.

Why Use Inheritance?

Inheritance provides many benefits:

✔ Code reusability

✔ Less duplication

✔ Easy maintenance

✔ Supports polymorphism

✔ Improves program structure

Real-World Example of Inheritance

Base Class: Employee

Subclass: Manager

A Manager is an Employee, but has extra responsibilities.

ConInheritance in Object-Oriented Programming (OOP)

Inheritance is one of the most important concepts in Object-Oriented Programming (OOP). It allows one class to reuse the properties and behaviors of another class. This helps in writing clean, reusable, and easy-to-maintain code.

What is Inheritance?

Inheritance is a mechanism where one class acquires the properties (variables) and behaviors (methods) of another class.

The class that provides features is called the Base Class (Parent Class)

The class that receives features is called the Subclass (Child Class)

👉 Inheritance represents an “IS-A” relationship

Example:

A Car is a Vehicle

Base Class (Parent Class)

The base class is the class whose properties and methods are inherited by another class.

Example:

Copy code

Java

class Vehicle {

int speed = 60;

void showSpeed() {

System.out.println(“Speed: “ + speed);

}

}

Here, Vehicle is the base class.

Subclass (Child Class)

The subclass is the class that inherits from the base class using keywords like:

extends (Java)

: (Python)

Example:

Copy code

Java

class Car extends Vehicle {

void showType() {

System.out.println(“This is a car”);

}

}

Here, Car is the subclass that inherits from Vehicle.

Object Creation in Inheritance

An object of the subclass can access members of:

Its own class

The base class

Copy code

Java

public class Main {

public static void main(String[] args) {

Car c = new Car();

c.showSpeed(); // from base class

c.showType(); // from subclass

}

}

Member Access Rules in Inheritance

Access to class members depends on access modifiers.

Common Access Modifiers:

public

protected

default

private

Access Rules Table (Java)

Access Modifier

Same Class

Same Package

Subclass

Outside Package

public

✔

✔

✔

✔

protected

✔

✔

✔

❌

default

✔

✔

❌

❌

private

✔

❌

❌

❌

Example with Access Modifiers:

Copy code

Java

class Parent {

public int a = 10;

protected int b = 20;

int c = 30; // default

private int d = 40;

}

Copy code

Java

class Child extends Parent {

void display() {

System.out.println(a); // allowed

System.out.println(b); // allowed

System.out.println(c); // allowed (same package)

// System.out.println(d); // NOT allowed

}

}

❌ Private members cannot be inherited.

Why Use Inheritance?

Inheritance provides many benefits:

✔ Code reusability

✔ Less duplication

✔ Easy maintenance

✔ Supports polymorphism

✔ Improves program structure

Real-World Example of Inheritance

Base Class: Employee

Subclass: Manager

A Manager is an Employee, but has extra responsibilities.

Conclusion

Inheritance helps classes share common behavior while allowing specialization. Understanding base classes, subclasses, and member access rules is essential for mastering OOP concepts and building real-world applications.clusion

Inheritance helps classes share common behavior while allowing specialization. Understanding base classes, subclasses, and member access rules is essential for mastering OOP concepts and building real-world applications.