Unit-2 Revision quiz

Which one is correct declaration for implementing two interfaces?

• class C implements A, B {}

• class C implements A, implements B {}

• class C implements A extends B {}

• class C extend A, B {}

which type of inheritance is not allowed in java directly

• Multi level

• Multiple

• Hierarhical

• single

Suppose the class Undergraduate extends the class Studentwhich extends the class Person. Given the following variable declaration:

Person p = new Person();

Student s = new Student();

Undergraduate ug = new Undergraduate();

Which of the following assignments are legal?

p =ug;

p = newUndergraduate();

ug = newStudent();

ug =p;

s = newPerson();

• I andIV

• III, II andIV

• I and II

• III andIV

What will be the result of this code will be?

Interface A {

inti =111;

}

class B implements A { void methodB(){

i =222;

System.out.printl(i);

}

}

• There is no main () method so the program is notexecutable.

• The value of i will be printed as 111, as it is static and final bydefault.

• The value of i will be printed as 222, as it is initialized in classB.

• Compile timeerror

which keyword is used to inherit the properties from a class

• impements

• extends

• final

• static

Can we inherit all the properties from parent class

• yes all the propeties canbe inherited

• yes all the properties except private property

• yes all the properties except protected property

• yes all the properties except default property

Multiple inheritances in java can be achieved in java using

• packages

• classes

• interfaces

• none

class A

{

void disp(){

System.out.println(“Parent”);

}

}

class B extends A

{

void disp(){

System.out.println(“Child”);

}

}

class C

{

oublic static void main(String args[])

{

B ob=new B();

ob.disp();

}

}

What is the output for this program?

• Parent

• Child

• Parent

  Child

• None

final can be used with

• variable

• class

• method

• all the above

class A

{

public static void main(String args[])

{

final int a=10;

System.out.println(a);

a=a+10;

System.out.println(a);

}

}

What is the output of above program?

• 10

  20

• 20

  10

• 10

  10

• error