What are default methods in Java 8?

Interfaces can have default methods with implementation in Java 8 on later. Interfaces can have static methods as well, similar to static methods in classes. Default methods were introduced to provide backward compatibility for old interfaces so that they can have new methods without affecting existing code.

Are default methods bad?

Yes. They are still useful. They can contain non-static, non-final methods and attributes (protected, private in addition to public), which is not possible even with Java-8 interfaces. Default methods in Java interface enables interface evolution.

Why defaults methods in interface were added in Java 8?

Java 8 allows the interfaces to have default and static methods. The reason we have default methods in interfaces is to allow the developers to add new methods to the interfaces without affecting the classes that implements these interfaces.

What is the difference between default and static method in Java 8?

Differences between static and default methods in Java 8: 1) Default methods can be overriden in implementing class, while static cannot. 3) Both class and interface can have static methods with same names, and neither overrides other!

Can we override default method in Java interface 8?

Since Java8 static methods and default methods are introduced in interfaces. Unlike other abstract methods these are the methods can have a default implementation. If you have default method in an interface, it is not mandatory to override (provide body) it in the classes that are already implementing this interface.

Can we override default method in Java 8?

A default method cannot override a method from java. The reasoning is very simple, it’s because Object is the base class for all the java classes. So even if we have Object class methods defined as default methods in interfaces, it will be useless because Object class method will always be used.

Do abstract classes have default methods?

An abstract class can have abstract and non-abstract methods. From Java 8, it can have default and static methods also. Final Variables: Variables declared in a Java interface are by default final. An abstract class may contain non-final variables.

How many default methods can an interface have?

Multiple Defaults With default functions in interfaces, there is a possibility that a class is implementing two interfaces with same default methods. The following code explains how this ambiguity can be resolved. First solution is to create an own method that overrides the default implementation.

What is the difference between Java 8 interface and abstract class?

But, the main difference between an abstract class and an interface in Java 8 is the fact that an abstract class is a class and an interface is an interface. A class can have a state which can be modified by non-abstract methods but an interface cannot have the state because they can’t have instance variables.

CAN interface have more than one default method?

Multiple Defaults With default functions in interfaces, there is a possibility that a class is implementing two interfaces with same default methods. First solution is to create an own method that overrides the default implementation.

Can a default method be overridden?

you can override a default method of an interface from the implementing class.

Can abstract class have default method?