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OCPJP 6 Mock Exam -1

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Q 1 : What will be the output?

[code lang=”java”]
public class Test1{
public static void main(String[] args){
int arr[] = new int[3];
for(int i = 0;i < arr.length;i++){
System.out.println(arr[i]);
}
}
}
[/code]

Choose the one below:

  1. 0 0 0
  2. ArrayIndexoutOfBoundsException
  3. NullPointerException
  4. null null null

Q 2 : Which of the following are valid array declarations?

  1. int arr[] = new int[];
  2. float arr[10] = new fl
  3. double []arr = new double[10];
  4. None Of the Above.

Q 3 : What will be the output?

[code lang=”java”]
public class Test3{
public void method(){
System.out.println("Called");
}
public static void main(String[] args){
method();
}
}
[/code]

Choose the one below:

  1. “Called”
  2. Compiler
  3. Runtime
  4. Nothing

Q 4 : What will be the output?

[code lang=”java”]
public class Test4{
public static void method(){
System.out.println("Called");
}
public static void main(String[] args){
Test4 t4 = null;
t4.method();
}
}
[/code]

Choose the one below:

  1. “Called”
  2. Compiler
  3. Runtime Exception
  4. Nothing is printed in screen

Q 5 : What will be the output?

[code lang=”java”]
public class Test5{
public void Test5(){
System.out.println("Constructor1");
}
public Test5(){
System.out.println("Constructor2");
}
public static void main(String[] args){
Test5 t5 = new Test5();
}
}
[/code]

Choose the one below:

  1. “Constructor1”
  2. “Constructor2”
  3. “Constructor1″”Constructor2”
  4. Compiler Errror

Q 6 : What will be the output?

[code lang=”java”]
public class Test6{
public Test6(){
this(4);
}
public Test6(byte var){
System.out.println(var);
}
public static void main(String[] args){
Test6 t6 = new Test6();
}
}
[/code]

Choose the one below:

  1. 4
  2. 4 4
  3. Compiler Error
  4. Compiles and Runs without error

Q 7 : What will be the output?

[code lang=”java”]
public class Test7{
public Test7(){}
public Test7(Test7 ref){
this (ref,"Hai");
}
public Test7(Test7 ref,String str){
ref.Test7(str);
System.out.println("Hi");
}
public void Test7(String str){
System.out.println(str);
}
public static void main(String[] args){
Test7 t = new Test7();
Test7 t7 = new Test7(t);
}
}
[/code]

Choose the one below:

  1. HI
  2. hai
  3. Hai Hi
  4. Hi Hai

Q 8 : Which of the following are valid Constructors?

  1. public Test8(){}
  2. private void Test8(){}
  3. protected Test8(int k){}
  4. Test8(){}

Q 9 : Which of the following are valid method declarations?

  1. abstract method(){}
  2. abstrct void method(){}
  3. final void method(){}
  4. int method(){}

Q 10 : Which of the following are valid top-level class declarations?

  1. class Test10
  2. public class Test10
  3. final class Test10
  4. abstract final class Test10

Q 11 : transient keywaord can be used with?

  1. method
  2. variable
  3. class
  4. constructor

Q 12 : which of the following are valid combinations for class declaration?

  1. abstract final class Test12{}
  2. abstract static class Test12{}
  3. final static class Test12{}
  4. public final strictfp class Test12{}

Q 13 : which of the following are valid constructor signatures?

  1. public void className()
  2. public void className()
  3. private className()
  4. static className()

Q 14 : Which of the following modifiers can be used with top class declaration?

  1. static
  2. private
  3. public
  4. final
  5. abstract

Q 15 : Which of the following are valid array declarations?

  1. int arr[] = new int[];
  2. int arr[][] = new int [10][10];
  3. float arr[][] = new float[][10];
  4. float arr[] = new float[10];

Q 16 : What will be the output of the following program?

[code lang=”java”]
public class Test1 {
static{
System.out.println("Static");
}
{
System.out.println("Instance");
}
public void Test1(){
System.out.println("Constructor");
}
public static void main(String[] args) {
Test1 t = null;
}
}
[/code]

Choose the one below:

  1. Instance Static
  2. Static Instance
  3. Static
  4. Static Instance Constructor

Q 17 : What will be the output of the following program?

[code lang=”java”]
class Sup{
public Sup(String str){
System.out.println("Super class");
}
}

public class Test2 extends Sup{
public Test2(){
System.out.println("Sub class");
}
public static void main(String[] args) {
Test2 t2 = new Test2();
}
}
[/code]

Choose the one below:

  1. Super class,SubClass
  2. Super class
  3. Sub class
  4. Compiler Error

Q 18 : What will be the output of the following program?

[code lang=”java”]
public class Test3 {
public static void main(String[] args) {
System.out.println("Main Method1");
}
public static void main(String args){
System.out.println("Main Method2");
}
}
[/code]

Choose the one below:

  1. Main Method1
  2. Main Method1 Main Method2
  3. Main Method2
  4. Runtime Exception

Q 19 : What will be the output of the following program?

[code lang=”java”]
public class Test4 {
public static void main(String args) {
System.out.println("Sample Program");
}
}
[/code]

Choose the one below:

  1. Sample Program
  2. Compiler Error
  3. Runtime Exception
  4. None

Q 20 : What will be the output of the following program?

[code lang=”java”]
class Sup1{
public Sup1(){
System.out.println("Hai");
}
private Sup1(String str){
System.out.println(str);
}
}

public class Test5 extends Sup1{
private Test5(String str){
System.out.println(str);
super();
}
public static void main(String[] args) {
Test5 t5 = new Test5("HI");
}
}
[/code]

Choose the one below:

  1. Hai,Hi,Hi
  2. Hai,Hi
  3. Hi,Hi
  4. Compiler Error

Q 21 : Which of the following are not a wrapper class?

  1. String
  2. Integer
  3. StringBuffer
  4. Boolean

Q 22 : Select the correct syntax for main method :

  1. public void main(String args[])
  2. public static void main(String args)
  3. public static void Main(String args[])
  4. None of the Above

Q 23 : Which of the following are not a valid declarations?

  1. float f = 1;
  2. float f = 1.2f;
  3. float f = 1.2;
  4. float f = (float)1.2;

Q 24 : String s1 = new String(“hi”);

[code lang=”java”]
String s2 = "hi";
System.out.println(s1 ==s2);
System.out.println(s1.equals(s2));
[/code]

  1. false true
  2. true false
  3. true true
  4. None of the above.

Q 25 : Integer i = new Integer(0);

[code lang=”java”]
Float f = new Float(0);
System.out.println(i==f);
System.out.println(i.equals(f));
[/code]

  1. true false
  2. false true
  3. true true
  4. Compiler error

Answers

Q 1 : 1 is correct. Local Array variables are initialized to their default values.

Q 2 : 3 is correct. double []arr = new double[10];

Q 3 : 2 is correct. Compiler Error.

Q 4 : 1 is correct. “Called”.

Q 5 : 2 is correct. “Constructor2”.

Q 6 : 3 is correct. Compiler Error.

Q 7 : 3 is correct. Hai Hi.

Q 8 : 1 is correct. public Test8(){}.
3 is correct. protected Test8(int k){}.

Q 9 : 3 is correct. final void method(){}.
4 is correct. int method(){}.

Q 10 : 1 is correct. class Test10.
2 is correct. public Test10.
3 is correct. final Test10.

Q 11 : 2 is correct. variable.

Q 12 : 3 is correct. final static class().
4 is correct. public final strictfp class{}.

Q 13 : 2 is correct. public className().
3 is correct. private className().

Q 14 : 3 is correct. public.
4 is correct. final.
5 is correct. abstract.

Q 15 : 2 is correct. int arr[][] = new int [10][10];
4 is correct. float arr[] = new float[10];

Q 16 : 3 is correct. Static.

Q 17 : 4 is correct. Compiler Error.

Q 18 : 1 is correct. Main Method1.

Q 19 : 3 is correct. Runtime Exception.

Q 20 : 4 is correct. Compiler Error.

Q 21 : 1 is correct. String.
4 is correct. String Buffer.

Q 22 : 4 is correct. None of the Above.

Q 23 : 3 is correct. float f = 1.2;

Q 24 : 1 is correct. false true.

Q 25 : 4 is correct. Compiler error.

About Krishna Srinivasan

He is Founder and Chief Editor of JavaBeat. He has more than 8+ years of experience on developing Web applications. He writes about Spring, DOJO, JSF, Hibernate and many other emerging technologies in this blog.

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