NIELIT Scientific Assistant A 2020 November: 74

Question

What is the output of the following program?

abstract class sum
{
    public abstract int sumOfTwo(int n1, int n2);
    public abstract int sumOfThree(int n1, int n2, int n3);
    public void disp(){
        System.out.println("Method of class Sum");
    }
}

class DemoAbstract1 extends Sum
{
    public int sumOfTwo(int num1, int num2)
    {
        return num1+num2;
    }
    public int sumOfThree(int num1, int num2, int num3)
    {
        return num1+num2+num3;
    }
    
    public static void main(String args[]){
        Sum obj=new DemoAbstract1();
        System.out.println(obj.sumOfTwo(3,7));
        System.out.println(obj.sumOfThree(4,3,19));
        obj.disp();
    }
}

• A. $10\\26\\\text{Method of class Sum}$
• B. $26\\10\\\text{Method of class Sum}$
• C. $\text{Method of class Sum}\\26\\10$
• D. $\text{Error}$

Comments

option A is the answer

Answer 1

Firstly an object of DemoAbstract will be created.

When you call System.out.println(obj.sumOfTwo(3,7)) then it will return 10

When you call System.out.println(obj.sumOfThree(4,3,19)) then it will return 26

Lastly, when you call obj.disp() then "Method of class Sum" will be printed. 

So, Option (A) is Correct.