Difference Between Abstract Class and Interface (With Table)

Developers consider Java to be one of the popular programming languages, despite his generation and the rise of python, referring to a guarantee that the language will be an alternative to contributing factors to the development in the coming years. Abstract class and interfac are the two main parts of the Java programming language.

The basic difference between an Abstract Class and an Interface is that an Abstract Class can have access modifiers whereas an interface has no access modifiers and everything in it is assumed to be a public modifier.

Abstract Class vs Interface

The main difference between Abstract class and Interface is that An Abstract class has data fields and can be extended to only one Abstract class at a time. On the other hand, there are no data fields but the Interface can extend up to several Interfaces, however, can only extend Interfaces.

An Abstract class is referred to as the class described with an Abstract keyword. It is the summation of common subclasses that includes at least one Abstract method. It can be determined in several ways. The Abstract class also minimizes the time for coding. Abstract classes are considered an excellent choice to avoid code duplication.

The Interface is a blueprint used as a tool to execute the class. An Interface is a collection of different abstract methods, but mostly conceptual rather than explicit abstract classes. Interfaces can only have final and static variables, no data fields.

Comparison Table Between Abstract Class and Interface

Parameters Of Comparison Abstract ClassInterface
DefinitionSummation of different classes that include at least one Abstract method.The interface is the blueprint tool used for representing in class.
Access ModifierAn Abstract Class has access modifiers used for setting accessibility of classes and methods and other members.The interface abstains access modifiers and everything is within and presumed to be a public modifier.
Data FieldsAn Abstract Class can have a data field.The Interface cannot have data fields.
Defining FieldsUsers in the Abstract class can define both fields and constant.Users in the interface cannot define any fields.
Variable Type In Abstract class, it can have final, non-final, static, and nonstatic variables.The Interface can have final and static variables.

What is Abstract Class?

An Abstract class is referred to as the class described with an Abstract keyword. It is the summation of common subclasses that includes at least one Abstract method.

An abstract class is referred to as a template used to store useful programming data methods and members. In Java Instrumentation, Abstract Class is not possible directly but Abstract Class can be informed of subclasses.

Abstract Class provides developers with options for hiding the code execution, which helps to carry out the data abstraction process efficiently. It also minimizes the time for coding. Abstract methods are considered a good way to avoid code duplication.

For using an abstract class in Java there are certain rules to be followed.

  1. When declaring an abstract class it is important to have an Abstract keyword.
  2. To carry out Abstract Class in Java instrumentation at least one Abstract method is required, one cannot have an Abstract class directly.
  3. In the Abstract class, all final methods should be included.
  4. Static and constructor methods should be included in Abstract Class.

An abstract class is considered important as it helps in writing short-length coats and also reduces the chances of repetition of code the showing reusability of code.

What is Interface?

Interfaces are called blueprints and are a tool for representing them in classes. Abstract classes and Interface cannot have different variables and methods. But methods used in interface are abstract by default.

This Interface helps to understand what an Abstract Class is supposed to do. The Interface has a collection of different methods that the class can apply. The Interface is used for attaining Abstraction. The Interface has several provisions that are not supported in Abstract classes.

The Interface is used for carrying out loose coupling, where components are weekly related to each other. The interface is mainly used for carrying out several provisions and abstractions in Java.

The main property of Java Interfaces are

  1. Abstract keyword is not required when declaring the interface. It is considered completely Abstract.
  2. For every abstract method, each interface is also considered Abstract and there is no need for abstract keywords required.
  3. Each interface method is considered public.

The advantage of Java Interfaces is that they can be used for different data abstraction methods and also supports many functions in Java.

Main Differences Between Abstract Class and Interface

  1. An Abstract class is also called a base class, which defines all the functions and members of the class, where the Interface is considered as a tool to specify the functionality of the Abstract class.
  2. Abstract classes can have data fields and constants, whereas Interfaces cannot have data fields.
  3. Abstract Class is considered as the superclass whereas Interface is considered as a subclass.
  4. Abstract Class has an access modifier whereas Interface does not have any access modifier and everything is assumed to be a public modifier.
  5. In an Abstract class, full abstraction is unavailable, but an Interface can provide full abstraction.


Both Abstract class and Interface are the main parts of the Java instrumentation program. Both help in abstraction and are used for different functions.

The dissimilarity between Abstract class and Interface is the use of keyboard Abstract. The keyword abstract is necessary for creating abstract classes. To further design the system, it is considered the best combination to combine abstract classes and interfaces in Java.


  1. https://dl.acm.org/doi/abs/10.1145/1040305.1040314
  2. https://link.springer.com/content/pdf/10.1007/978-1-4302-0140-3_12.pdf