JAVA - CLASSES AND METHODS MCQs

What is the stored in the object obj in following lines of code?

box obj;

Which of these keywords is used to make a class?

Which of the following is a valid declaration of an object of class Box?

Which of these operators is used to allocate memory for an object?

Which of these statement is incorrect

What is the output of this program?

    class main_class 
    {
        public static void main(String args[])
        {
            int x = 9;
            if (x == 9) 
            { 
                int x = 8;
                System.out.println(x);
            }
        } 
    }

Which of the following statements is correct

What is the output of this program?

    class box 
    {
        int width;
        int height;
        int length;
    } 
    class mainclass 
    {
        public static void main(String args[]) 
        {        
             box obj = new box();
             obj.width = 10;
             obj.height = 2;
             obj.length = 10;
             int y = obj.width * obj.height * obj.length; 
             System.out.print(y);
        } 
    }

What is the output of this program?

    class box 
    {
        int width;
        int height;
        int length;
    } 
    class mainclass 
    {
        public static void main(String args[]) 
        {        
            box obj1 = new box();
            box obj2 = new box();
            obj1.height = 1;
            obj1.length = 2;
            obj1.width = 1;
            obj2 = obj1;
            System.out.println(obj2.height);
        } 
    }

What is the output of this program?

   class box 
   {
        int width;
        int height;
        int length;
   } 
    class mainclass 
    {
        public static void main(String args[]) 
        {        
            box obj = new box();
            System.out.println(obj);
        } 
    }

What is the return type of a method that does not return any value?

What is the process of defining more than one method in a class differentiated by method signature?

Which of the following is a method having same name as that of it’s class?

Which method can be defined only once in a program?

What is the output of this program?

    class box 
    {
        int width;
        int height;
        int length;
        int volume;
        void volume(int height, int length, int width) 
        {
             volume = width*height*length;
        } 
    }    
    class Prameterized_method
    {
        public static void main(String args[])
        {
            box obj = new box();
            obj.height = 1;
            obj.length = 5;
            obj.width = 5;
            obj.volume(3,2,1);
            System.out.println(obj.volume);        
        } 
     }

What is the output of this program?

   class equality 
    {
        int x;
        int y;
        boolean isequal()
        {
            return(x == y);  
        } 
    }    
    class Output 
    {
        public static void main(String args[])
        {
            equality obj = new equality();
            obj.x = 5;
            obj.y = 5;
            System.out.println(obj.isequal());
        } 
    }

Which keyword is used by the method to refer to the object that invoked it?

Which of the following is a method having same name as that of its class?

Which operator is used by Java run time implementations to free the memory of an object when it is no longer needed?

Which function is used to  perform some action when the object is to be destroyed?