Default methods were introduced in Java 8 to provide a way to add new functionality to interfaces without breaking the existing implementation. Prior to Java 8, interfaces were limited to declaring methods that had to be implemented by the implementing class. However, with default methods, interfaces can now provide default implementation for methods. This article will explore the concept of default methods in Java and how they can be used to add new functionality to existing interfaces.
What are default methods?
A default method is a method defined in an interface that provides a default implementation. When a class implements an interface that contains a default method, the class can either override the default method or use the default implementation provided by the interface. Default methods are declared using the default keyword and can have an implementation. They are also marked as public.
Syntax of a default method:
The syntax of a default method in Java is as follows:
public interface ExampleInterface {
default void exampleMethod() {
// default implementation
}
}
In this example, we have declared a default method called exampleMethod() in an interface called ExampleInterface.
Usage of default methods:
Default methods are used to add new functionality to existing interfaces. This can be useful when we want to add new features to an existing interface without breaking the existing implementation. For example, suppose we have an interface called Shape that has a method called getArea(). We can add a default method called getColor() to the Shape interface without breaking the existing implementation of the getArea() method. This would allow us to get the color of a shape without having to modify the existing Shape implementations.
Benefits of default methods:
Default methods provide several benefits in Java programming. Some of these benefits include:
Backward compatibility: Default methods allow new features to be added to an existing interface without breaking the existing implementation.
Code reuse: Default methods can be used to provide common functionality to multiple classes that implement the same interface.
Reduced code duplication: Default methods can be used to provide default implementations for methods, which can help to reduce code duplication.
Improved readability: Default methods can improve the readability of code by providing a standard implementation for common methods.
Conclusion:
Default methods are a powerful feature of Java 8 that allow new functionality to be added to existing interfaces without breaking the existing implementation. They provide several benefits, including backward compatibility, code reuse, reduced code duplication, and improved readability. By using default methods, Java programmers can write more efficient and maintainable code that is easier to read and understand.
