A key idea in object-oriented programming is inheritance, which enables classes to take on traits and characteristics from other classes. Contrary to some other programming languages, Java does not explicitly enable multiple inheritance, which allows a class to derive from numerous classes. But don’t worry! Java offers alternate methods so you can get the rewards of multiple inheritance without breaking its single inheritance rule. We’ll examine these strategies in this blog post and show you how to enable multiple inheritance in Java effectively.

First, we Understand the issue of multiple inheritance.

Conflicts can emerge as a result of multiple inheritance if a class derives from two classes that share a superclass, a situation known as the “diamond problem.” This ambiguity can lead to complexity, making the code more difficult to maintain and comprehend. Java encourages single inheritance, enabling a class to derive from just one superclass, to prevent these problems. We can implement Multiple inheritances with different solutions.

Conflicts can emerge as a result of multiple inheritance if a class derives from two classes that share a superclass, a situation known as the “diamond problem.” This ambiguity can lead to complexity, making the code more difficult to maintain and comprehend. Java encourages single inheritance, enabling a class to derive from just one superclass, to prevent these problems.

Solution 1: Using Interface for Multiple Inheritance

Java introduces interfaces to overcome the drawbacks of multiple inheritance. Classes can provide specific behavior by implementing the contract defined by an interface. Classes can implement several interfaces, which effectively achieves the benefits of multiple inheritance, even though they cannot inherit multiple classes.

Create interfaces that specify the methods a class should implement in the first step. Each interface could stand for a distinct function or feature.

Code with Explanation

interface Father {
    void Car();
}

interface Son {
    void Drive();
}
Code language: PHP (php)

The second step is to implement the interfaces in your class by giving the methods specified in the interfaces concrete implementations.

Code with Explanation

class Interact implements Father, Son {

    @Override
    public void Car() {
        // Implement your code for car
    }

    @Override
    public void Drive() {
        // Implement your code for drive
    }
}
Code language: PHP (php)

Utilize the Implementations in Step 3: You may now utilize instances of your class as though multiple inheritance were supported. They are objects that are both drawable and audible.

Code with Explanation

public class Main {
    public static void main(String[] args) {
        Interact obj = new Interact();
        obj.Car();
        obj.Drive();
    }
}
Code language: JavaScript (javascript)

Solution 2  Using Default Method in Interface with java version 8 and Later

Interface default methods were first implemented in Java 8. These methods allow you to extend existing interfaces without causing the implementing classes to break because they contain default implementations.

• Specify Standard Methods: Specify default methods in an interface that offer generic functionality or empty implementations.

Code with Explanation

interface Father {
    void Car();

    default void Rate() {
        // Implement your code
    }
}

interface Son {
    void Drive();

    default void Learndrive() {
        // Implement your code
    }
}
Code language: JavaScript (javascript)

Implement and Override: If necessary, you can decide to override the default methods while implementing the interfaces.

Code with Explanation

class Interact implements Father, Son {

    @Override
    public void Car() {
        // Implement your code
    }

    @Override
    public void Drive() {
        // Implement your code
    }

    @Override
    public void Rate() {
        // Implement your code to override this method if needed.
    }

    @Override
    public void Learndrive() {
        // Implement your code to override this method if needed.
    }
}
Code language: PHP (php)

Conclusion

Despite not explicitly supporting multiple inheritance, Java provides strong workarounds through interfaces and default methods. These substitutes not only assist you in avoiding the diamond problem’s complications but also promote clean code organization and maintainability. You can efficiently obtain the advantages of multiple inheritance while complying with Java’s single inheritance rules by using interfaces. Your codebase can become more flexible, modular, and adaptive to changing requirements whether you use conventional interfaces or default methods.