WithoutBook

Education platform for interview prep, online tests, tutorials, and live practice

Build skills with focused learning paths, mock tests, and interview-ready content.

WithoutBook brings subject-wise interview questions, online practice tests, tutorials, and comparison guides into one responsive learning workspace.

Search the library

Prepare Interview

Ask Question

Mock Exams

Make Homepage

Bookmark this page

Question: How can you achieve Multiple Inheritance in Java?

Answer:

interface CanFight { 
	void fight(); 
}      

interface CanSwim { 
	void swim(); 
}      

interface CanFly { 
	void fly();
}
       
class ActionCharacter { 
	public void fight() {}
}       

class Hero extends ActionCharacter implements CanFight, CanSwim, CanFly { 
	public void swim() {}
	public void fly() {}
}

You can even achieve a form of multiple inheritance where you can use the *functionality* of classes rather than just the interface:

interface A { 
	void methodA();
} 

class AImpl implements A { 
	void methodA() { //do stuff }
}
 
interface B { 
	void methodB();
} 

class BImpl implements B { 
	void methodB() { //do stuff }
}
 
class Multiple implements A, B { 
	private A a = new A();
	private B b = new B();
	void methodA() { 
		a.methodA(); 
	}
	void methodB() { 
		b.methodB(); 
	}
}

This completely solves the traditional problems of multiple inheritance in C++ where name clashes occur between multiple base classes. The coder of the derived class will have to explicitly resolve any clashes. Don't you hate people who point out minor typos? Everything in the previous example is correct, except you need to instantiate an AImpl and BImpl. So class Multiple would look like this:

class Multiple implements A, B { 
	private A a = new AImpl();
	private B b = new BImpl();
	void methodA() { 
		a.methodA(); 
	}
	void methodB() { 
		b.methodB(); 
	}
}

Save For Revision

Bookmark this item, mark it difficult, or place it in a revision set.

Open My Learning Library

Is it helpful? Yes No

Most helpful rated by users: