Test : Java_16

This test contains 10 questions based on Java.
Each question answered correctly awards you 1 point and each incorrect answer has a penalty of -0.25 points, no points are deducted for unattempted answers.

Select Test Type

You Get +1 for each correct answer and -0.25 for each incorrect answer

Time Left - minutes :seconds

What is the output of this program?

 class box {
        int width;
        int height;
        int length;
        int volume;
        box() {
            width = 5;
            height = 5;
            length = 6;
        }
        void volume() {
             volume = width*height*length;
        } 
    }    
    class constructor_output {
        public static void main(String args[])
        {
            box obj = new box();
            obj.volume();
            System.out.println(obj.volume);        } 
        }
   }

100	150
200	250

B

Which of these have highest precedence?

()	++
*	>>

A

What is the output of this program?

class operators {
        public static void main(String args[]) 
        {    
             int x = 8;
             System.out.println(++x * 3 + " " + x);
        } 
    }

24 8	25 9
27 4	27 9

D

Which of the following operators can operate on a boolean variable? 1. && 2. == 3. ?: 4. +=

3 & 2	1 & 4
1, 2 & 4	1, 2 & 3

D

Given the code String s1 = "yes"; String s2 = "yes"; String s3 = new String(s1); Which of the following would equate to true? (A) s1 == s2 (B) s1 = s2 (C) s3 == s1 (D) s1.equals(s2) (E) s3.equals(s1)

(A), (C) & (E)	(A), (B) & (C)
(A), (D) & (E)	(D) & (E)

C

Which of these lines will give an error line 1 :int a=1; line 2 :float f=2; line 3 :double d=2.9;

line 1	line 2
line 3	none of these

D

no error since float can take integer value

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);        } 
    }

True	False
0	1

A

What is the output of this program?

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

0	1
2	Compilation Error

C

What is the output of this program?

interface calculate {
        int VAR = 0;
        void cal(int item);
    }
    class display implements calculate {
        int x;
        void cal(int item) {
            if (item < 2)
                x = VAR;
            else
                x = item * item;            
        }
    }
    class interfaces {
        public static void main(String args[]) {
            display arr[] = new display[3];
            arr[0].cal(0);    
            arr[1].cal(1);
            arr[2].cal(2);
            System.out.print(arr[0].x + " " + arr[1].x + " " + arr[2].x);
        }
    }

0 1 2	0 2 4
0 0 4	0 1 4

C

 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	3

C

This is a case of method overriding or dynamic polymorphism. Here the method display of class A gets overridden by the display method of class B. Thus when the call for display method is made, method of class B gets executed.

Finish Test