Data abstraction is the process of hiding certain details and showing only essential information to the user. Abstraction can be achieved with either abstract classes or interfaces (which you will learn more about in the next chapter). The abstract keyword is a non-access modifier, used for classes and methods:

Another way to achieve abstraction in Java, is with interfaces. An interface is a completely " abstract class " that is used to group related methods with empty bodies: To access the interface methods, the interface must be "implemented" (kinda like inherited) by another class with the implements keyword (instead of extends).

Apr 15, 2025 · Overall, abstract classes in Java are used to define a common interface or behavior that can be shared by multiple related classes, with specific implementations …

Only a single abstract class be get inherited by a class. A class can inherit several interfaces. An abstract class provides the complete code or simply the details which need to be overridden. The interface provides the signature rather than the code. It is comparatively faster than the interface.

What is difference between abstract class and interface in java: Abstract class is a way of implementing 0 to 100% abstraction whereas Interface is a way of implementing 100% abstraction.

Java provides the concept of abstraction through Abstract classes and interfaces. A class containing the keyword abstract in its declaration creates the abstract class.

Abstraction in Java is a powerful concept that allows us to create flexible and maintainable code. By using abstract classes and methods, we can define common behaviors for a group of related classes while allowing each class to implement these behaviors in its own unique way.

An interface is declared with the interface keyword. Interface can contain only abstract methods and static final data members Or Interface is a group of related abstract methods.

Mar 1, 2025 · StringFunction is a functional interface. In other words it is an interface with a single abstract method. An abstract method is a method without definition (without body). Such interfaces can be implemented using a lambda expression. As it is done in your example. So StringFunction exclaim = (s) -> s + "!"

The interface keyword is used to declare a special type of class that only contains abstract methods. To access the interface methods, the interface must be "implemented" (kinda like inherited) by another class with the implements keyword (instead of extends).