What is Default Method in Java?

Java 8 introduced a new feature called default methods, which allow developers to add new functionality to existing interfaces without breaking existing code. This article will explain what default methods are, how they work, and how they can be used to add new features to existing interfaces.

Introduction to Default Methods

Default methods are a new feature in Java 8 that allow developers to add new functionality to existing interfaces without breaking existing code. This is done by providing a default implementation of the new method in the interface itself.

Default methods enable developers to add new methods to existing interfaces that accept lambda expressions as parameters. This allows developers to write code that is more concise and expressive, and to add new features to existing interfaces without breaking existing code.

Benefits of Default Methods

Default methods provide several benefits to developers. First, they allow developers to add new features to existing interfaces without breaking existing code. This is important because it ensures that code written for older versions of the interface will still work with the new version.

Second, default methods enable developers to write code that is more concise and expressive. By using lambda expressions as parameters, developers can write code that is more concise and expressive than traditional Java code.

Third, default methods enable developers to add new functionality to existing interfaces without having to create a new interface. This is important because it allows developers to add new features to existing interfaces without having to create a new interface and rewrite existing code.

How Default Methods Work

Default methods are implemented by providing a default implementation of the new method in the interface itself. This default implementation is then used by the compiler when the interface is implemented by a class.

If the class does not provide an implementation of the method, then the default implementation is used. If the class does provide an implementation of the method, then the class’s implementation is used instead of the default implementation.

Using Default Methods

Default methods can be used to add new features to existing interfaces without breaking existing code. This is done by providing a default implementation of the new method in the interface itself.

The default implementation is then used by the compiler when the interface is implemented by a class. If the class does not provide an implementation of the method, then the default implementation is used. If the class does provide an implementation of the method, then the class’s implementation is used instead of the default implementation.

Default methods can also be used to add new methods that accept lambda expressions as parameters. This allows developers to write code that is more concise and expressive, and to add new features to existing interfaces without breaking existing code.

Conclusion

Default methods are a new feature in Java 8 that allow developers to add new functionality to existing interfaces without breaking existing code. Default methods enable developers to add new methods to existing interfaces that accept lambda expressions as parameters, allowing developers to write code that is more concise and expressive. Additionally, default methods enable developers to add new features to existing interfaces without having to create a new interface and rewrite existing code.