The difference between inheritance and composition in Java

Composition is a design technique where your class can have an instance of another class as a field of your class. Inheritance is a mechanism where an object can obtain the properties and behaviors of the parent object by extending the class.

Composition and inheritance both provide code reusability through related classes. When you use composition, we can also obtain the functionality of inheritance. Here are the differences.　

Serial Number	Key	Inheritance	Composition
1	Basic	Inheritance is a "is" relationship	Composition is a "has" relationship
2	Code Reuse	In inheritance, a class can only extend one interface, so you can only reuse code in one class	We can reuse code in multiple classes
3	Scope	Inheritance provides its functionality at compile time	Easily implement composition at runtime
4	Finally	We cannot reuse the code from the last class	It even allows code reuse from the final class
5	Methods	It exposes the public methods and protected methods of the superclass	It does not expose. They interact using the public interface.

Example of Inheritance

class Animal{
　　　String name = "Orio";
{}
class Dog extends Animal{
　　　String type = "Dog";
　　　public static void main(String args[]) {
　　　　　　Dog p = new Dog();
　　　　　　System.out.println("Name:")+p.name);
　　　　　　System.out.println("Type:")+p.type);
　　　{}
{}

Composition Example

public class Student {
{}
public class College {
　　　private Student student;
　　　public College() {
　　　　　　this.student = new Student();
　　　{}
{}

Basic Tutorial