Inheritance

Which of this keyword must be used to inherit a class?

• super

• this

• extends

• extent

A class member declared protected becomes a member of subclass of which type?

• public member

• private member

• protected member

• static member

class A

{

int i;

void display()

{

System.out.println(i);

}

}

class B extends A

{

int j;

void display()

{

System.out.println(j);

}

}

class inheritance_demo

{

public static void main(String args[])

{

B obj = new B();

obj.i=1;

obj.j=2;

obj.display();

}

}

• 0

• 1

• 2

• Compilation Error

What will be the output of the following Java program?

class A

{

int i;

}

class B extends A

{

int j;

void display()

{

super.i = j + 1;

System.out.println(j + " " + i);

}

}

class inheritance

{

public static void main(String args[])

{

B obj = new B();

obj.i=1;

obj.j=2;

obj.display();

}

}

• 2 2

• 3 3

• 2 3

• 3 2

Using which of the following, multiple inheritance in Java can be implemented?

• Interfaces

• Multithreading

• Protected methods

• Private methods

In order to restrict a variable of a class from inheriting to subclass, how variable should be declared?

• Protected

• Private

• Public

• Static

If super class and subclass have same variable name, which keyword should be used to use super class?

• super

• this

• upper

• classname

Which inheritance in java programming is not supported

• Multiple inheritance using classes

• Multiple inheritance using interfaces

• Multilevel inheritance

• Single inheritance

If class B is subclassed from class A then which is the correct syntax

• class B:A{}

• class B extends A{}

• class B extends class A{}

• class B implements A{}

Order of execution of constructors in Java Inheritance is

• Base to derived class

• Derived to base class

• Random order

• none