Java Interfaces Tutorial 📘

Java interfaces are fundamental to object-oriented programming, enabling abstraction and multiple inheritance. They define a contract for classes to follow, specifying methods that must be implemented. Here's a concise guide:

📌 What is an Interface?

An interface is a blueprint of a class that contains:

• Method declarations (no implementation)
• Constants (static final variables)
• Default methods (since Java 8)

Example:

public interface Animal {
    void makeSound(); // Abstract method
    int getLegs();    // Constant
}

🔧 Key Features of Interfaces

• Abstraction: Hide implementation details
• Multiple Inheritance: A class can implement multiple interfaces
• Polymorphism: Enable objects to be treated as instances of their interfaces

🔄 Implementing an Interface

To implement an interface:

1. Use implements keyword
2. Provide implementation for all methods

public class Dog implements Animal {
    @Override
    public void makeSound() {
        System.out.println("Bark!");
    }

    @Override
    public int getLegs() {
        return 4;
    }
}

🧠 Interface vs Abstract Class

📚 Further Reading

Learn more about advanced Java topics:
Java Advanced Topics

For visual learners, check out this diagram: