Can we declare an abstract method, private, protected, public or default in java?

A method which does not have body is known as abstract method. It contains only method signature with a semi colon and, an abstract keyword before it.

public abstract myMethod();

To use an abstract method, you need to inherit it by extending its class and provide implementation to it.

Declaring an abstract method private

If a method of a class is private, you cannot access it outside the current class, not even from the child classes of it.

But, incase of an abstract method, you cannot use it from the same class, you need to override it from subclass and use.

Therefore, the abstract method cannot be private.

If, you still try to declare an abstract method final a compile time error is generated saying “illegal combination of modifiers − abstract and private”.

Example

In the following Java program, we are trying to declare an abstract method private.

abstract class AbstractClassExample {
   private static abstract void display();
}

Compile time error

On compiling, the above program generates the following error.

AbstractClassExample.java:2: error: illegal combination of modifiers: abstract and private
   private static abstract void display();
                              ^
1 error

Declaring an abstract method protected

Yes, you can declare an abstract method protected. If you do so you can access it from the classes in the same package or from its subclasses.

(Any you must to override an abstract method from the subclass and invoke it.)

Example

In the following Java program, we are trying to declare an abstract method protected.

 Live Demo

abstract class MyClass {
   protected abstract void display();
}
public class AbstractClassExample extends MyClass{
   public void display() {
      System.out.println("This is the subclass implementation of the display method ");
   }
   public static void main(String args[]) {
      new AbstractClassExample().display();
   }
}

Output

This is the subclass implementation of the display method

Maruthi Krishna

Published on 03-Jul-2019 14:18:44

• Related Questions & Answers
• Can we declare main() method as private or protected or with no access modifier in java?
• Can we declare an abstract method final or static in java?
• Can we declare interface members as private or protected in java8?
• Can we declare a top level class as protected or private in Java?
• What are private, public, default and protected access Java modifiers?
• Can we declare the variables of a Java interface private and protected?
• Can we declare a main method as private in Java?
• Can we have a private method or private static method in an interface in Java 9?
• Can we define an abstract class without abstract method in java?
• Can we declare a constructor as private in Java?
• Difference between private, public, and protected modifiers in C++
• Difference between private, public, and protected inheritance in C++
• Can we override a private or static method in Java
• Can we override a protected method in Java?
• Can we declare the method of an Interface final in java?