Java Methods Online Test – 3

1. What is the process of defining a method in a subclass having same name & type signature as a method in its superclass?

2. What will be the output of the following Java program?

 class Alligator 
 {
  public static void main(String[] args) 
   {
   int []x[] = {{1,2}, {3,4,5}, {6,7,8,9}};
   int [][]y = x;
   System.out.println(y[2][1]);
   }
 }

3. What will be the output of the following Java program?

 
    class A 
    {
        int i;
        public void display() 
        {
            System.out.println(i);
        }    
    }    
    class B extends A 
   {
        int j;
        public void display() 
        {
            System.out.println(j);
        } 
    }    
    class Dynamic_dispatch 
   {
        public static void main(String args[])
        {
            B obj2 = new B();
            obj2.i = 1;
            obj2.j = 2;
            A r;
            r = obj2;
            r.display();     
        }
   }

4. At line number 2 in the following code, choose 3 valid data-type attributes/qualifiers among "final, static, native, public, private, abstract, protected"

public interface Status
   {
        /* insert qualifier here */ int MY_VALUE = 10;
   }

5. What will be the output of the following Java program?

 
  class Abc
  {
      public static void main(String[]args)
      {
          String[] elements = { "for", "tea", "too" };
          String first = (elements.length > 0) ? elements[0]: null;
      }
  }

6. Which of these is correct way of calling a constructor having no parameters, of superclass A by subclass B?

7. What will be the output of the following Java program?

 
   final class A 
    {
         int i;
    }    
    class B extends A 
    {
        int j;
        System.out.println(j + " " + i);  
    }    
    class inheritance 
    {
        public static void main(String args[])
        {
            B obj = new B();
            obj.display();     
        }
   }

8. Which of this keyword can be used in a subclass to call the constructor of superclass?

9. Which of these keywords can be used to prevent Method overriding?

10. Which of these is supported by method overriding in Java?