Questions and answers for exam Preparation

MCQs

Total Questions : 31 | Page 3 of 4 pages

Question 21. Class MyClass{
      MyClass(){
            System.out.print("one");
      }
      public void myMethod(){
            this();
            System.out.print("two");
      }
}

public class TestClass{
      public static void main(String args[]){
            MyClass obj = new MyClass();
            obj.myMethod();
      }
}

two one one
one one two
one Exception
Compilation Error
None of these

Discuss Question

Answer: Option D. -> Compilation Error

Question 22. Class MyClass{
int i;
int j;
public MyClass(int i, int j){
this.i = i;
this.j = j;
}
public void call(){
System.out.print("One");
}
}
public class Test{
public static void main(String args[]){
MyClass m = new MyClass(); //line 1
m.call(); //line 2
}
}

One
Compilation fails due to an error on line 1
Compilation fails due to an error on line 2
Compilation succeed but no output.

Discuss Question

Answer: Option B. -> Compilation fails due to an error on line 1

Question 23. Determine output:
public class Test{
public static void main(String args[]){
MyClass obj = new MyClass();
obj.val = 1;
obj.call(obj);
System.out.println(obj.val);
}
}
class MyClass{
public int val;
public void call(MyClass ref){
ref.val++;
}
}

1
2
3
Compilation Error
None of these

Discuss Question

Answer: Option B. -> 2

Question 24. Public class MyClass{ }
For the above class(MyClass) what is the correct way of declaring constructor?

MyClass(){}
MyClass(void) {}
public MyClass(){}
public MyClass(void){}
1 and 3

Discuss Question

Answer: Option E. -> 1 and 3

Question 25. What is the output for the below code ?
1. public class A{
2. int add(int i, int j){
3. return i+j;
4. }
5. }
6. public class B extends A{
7. public static void main(String argv[]){
8. short s = 9;
9. System.out.println(add(s,6));
10. }
11.}

Compile fail due to error on line no 2
Compile fail due to error on line no 9
Compile fail due to error on line no 8
15
None of these

Discuss Question

Answer: Option B. -> Compile fail due to error on line no 9

Question 26. What will be the output?
public class Test{
public static void main(String[] args){
String value = "abc";
changeValue(value);
System.out.println(value);
}
public static void changeValue(String a){
a = "xyz";
}
}

abc
xyz
Compilation fails
Compilation clean but no output
None of these

Discuss Question

Answer: Option A. -> abc

Question 27. What is the output for the below code?
public class Test{
public static void printValue(int i, int j, int k){
System.out.println("int");
}
public static void printValue(byte...b){
System.out.println("long");
}
public static void main(String... args){
byte b = 9;
printValue(b,b,b);
}
}

long
int
Compilation fails
Compilation clean but throws RuntimeException
None of these

Discuss Question

Answer: Option B. -> int

Question 28. What is the output for the below code ?
class A{
public A(){
System.out.println("A");
}
public A(int i){
this();
System.out.println(i);
}
}
class B extends A{
public B(){
System.out.println("B");
}
public B(int i){
this();
System.out.println(i+3);
}
}
public class Test{
public static void main (String[] args){
new B(5);
}
}

A B 8
A 5 B 8
A B 5
B 8 A 5
None of these

Discuss Question

Answer: Option A. -> A B 8

Question 29. Class A{
A(String s){}
A(){}
}
1. class B extends A{
2. B(){}
3. B(String s){
4. super(s);
5. }
6. void test(){
7. // insert code here
8. }
9. }
Which of the below code can be insert at line 7 to make clean compilation ?

A a = new B();
A a = new B(5);
A a = new A(String s);
All of the above
None of these

Discuss Question

Answer: Option A. -> A a = new B();

Question 30. Which of these is a legal definition of a method named examveda assuming it throws IOException, and returns void. Also assume that the method does not take any arguments. Select the one correct answer.