Quiz In Java
Test your Knowledge in Java by answering the questions. Once your done you will find out your own strengths and weekness.
- 1.
8.2 Q1: The _________ of a class are also called the public services or the public interface that the class provides to its clients.
- A.
Public constructors.
- B.
public instance variables.
- C.
public methods
- D.
All of the above.
Correct Answer
C. public methods -
- 2.
Which of the following should usually be private?
- A.
Methods.
- B.
Constructors
- C.
Variables (or fields).
- D.
All of the above.
Correct Answer
C. Variables (or fields). -
- 3.
Which of the following statements is true?
- A.
Methods and instance variables can both be either public or private.
- B.
Information hiding is achieved by restricting access to class members via keyword public.
- C.
The private members of a class are directly accessible to the client of a class.
- D.
None of the above is true.
Correct Answer
A. Methods and instance variables can both be either public or private. -
- 4.
Having a this reference allows:
- A.
A method to refer explicitly to the instance variables and other methods of the object on which the method was called.
- B.
A method to refer implicitly to the instance variables and other methods of the object on which the method was called.
- C.
An object to reference itself.
- D.
All of the above.
Correct Answer
D. All of the above. -
- 5.
A constructor cannot:
- A.
Be overloaded.
- B.
Initialize variables to their defaults.
- C.
Specify return types or return values.
- D.
Have the same name as the class.
Correct Answer
C. Specify return types or return values. -
- 6.
8.5 Q2: Constructors:
- A.
Initialize instance variables.
- B.
When overloaded, can have identical argument lists.
- C.
When overloaded, are selected by number, types and order of types of parameters.
- D.
A and c.
Correct Answer
D. A and c. -
- 7.
A programmer-defined constructor that has no arguments is called a ________.
- A.
Zero-argument constructor.
- B.
No-argument constructor.
- C.
Default constructor
- D.
Main constructor.
Correct Answer
B. No-argument constructor. -
- 8.
Composition is sometimes referred to as a(n) ________.
- A.
Is-a relationship.
- B.
Has-a relationship.
- C.
Many-in-one relationship.
- D.
One-to-many relationship
Correct Answer
B. Has-a relationship. -
- 9.
Static class variables:
- A.
Are final.
- B.
Are public
- C.
Are private
- D.
Are shared by all objects of a class
Correct Answer
D. Are shared by all objects of a class -
- 10.
Which syntax imports all static members of class Math?
- A.
Static import java.lang.Math.*.
- B.
Import static java.lang.Math.*.
- C.
static import java.lang.Math
- D.
Import static java.lang.Math
Correct Answer
B. Import static java.lang.Math.*. -
- 11.
A package is:
- A.
A directory structure used to organize classes and interfaces.
- B.
A mechanism for software reuse
- C.
A group of related classes and interfaces
- D.
All
Correct Answer
D. All -
- 12.
A class within a package must be declared public if
- A.
It will be used only by other classes in the same package
- B.
It will be used by classes that are not in the same package
- C.
It is in the same directory as the other classes in the package.
- D.
It has a unique name
Correct Answer
B. It will be used by classes that are not in the same package -
- 13.
Consider the statement package com.deitel.jhtp6.ch08; Which of the following is true?
- A.
The statement declares a package that exists at deitel.com
- B.
The statement uses the Sun Microsystems convention of package naming
- C.
The statement should be placed inside the class declaration
- D.
The statement will generate a compile time error
Correct Answer
B. The statement uses the Sun Microsystems convention of package naming -
- 14.
The import declaration import java.util.*; is known as a ________.
- A.
Single-type-import declaration.
- B.
All-type-import declaration
- C.
Multiple-import declaration
- D.
Type-import-on-demand declaration
Correct Answer
D. Type-import-on-demand declaration -
- 15.
The import declaration import *; ________.
- A.
Causes a compilation error
- B.
Imports all classes in the library.
- C.
Imports the default classes in the library
- D.
Imports the classes in package java.lang
Correct Answer
A. Causes a compilation error -
- 16.
Which Man class properly represents the relationship "Man has a best friend who is a Dog"? A. class Man extends Dog { } B. class Man implements Dog { } C. class Man { private BestFriend dog; } D. class Man { private Dog bestFriend; } E. class Man { private Dog; } F. class Man { private BestFriend; }
- A.
A
- B.
B
- C.
C
- D.
D
- E.
E
- F.
F
Correct Answer
D. D -
- 17.
What will be the output of the following program class A { public static void main(String[] args) { System.out.println(getWelcomeMessage()); } static String getWelcomeMessage() { return "Welcome!!!"; } }
- A.
GetWelcomeMessage()
- B.
GetWelcomeMessage
- C.
Welcome!!!
- D.
It would give a compilation error
Correct Answer
C. Welcome!!! -
- 18.
What will the following output on the screen? for (int i = 0; i < 5; i++) { System.out.print("*"); }
- A.
* * * * *
- B.
*****
- C.
******
- D.
* * * * * *
- E.
None of the above
Correct Answer
B. *****Explanation
It will only output 5 stars one after the other on the same line, because print is being used and not println. The counter i starts from 0, then it will execute the body of the for loop while i is less than 5. It would have output 6 stars if it was iRate this question:
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- 19.
What is the return types of the following body of a method { int i = 10; return 3 * i; }
- A.
Int
- B.
Long
- C.
Double
- D.
30
- E.
None of the above
Correct Answer
A. Int -
- 20.
Will the following compile? int i = 0; for ( ; i < 5 ; ) { System.out.println(i); i++; }
- A.
Yes
- B.
No
Correct Answer
A. YesExplanation
The for loops consists of
for (; ; )
All of these are optional and you can leave any of them out. Try experimenting it on BlueJ.Rate this question:
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- 21.
What will this output? System.out.println(4 + 5 * 2);
- A.
14
- B.
18
- C.
None of the above
Correct Answer
A. 14Explanation
The * operator has a higher precedence than the plus operatorRate this question:
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- 22.
Which is the correct boolean expression which gives the following meaning: The value of x is greater than 1000 and x is smaller or equal to 2000
- A.
X >= 1000 && x
- B.
X > 1000 && x < 2000
- C.
X < 1000 && x >= 2000
- D.
X > 1000 && x
- E.
None of the above
Correct Answer
D. X > 1000 && x -
- 23.
Which of the following is NOT a strength of Java language?
- A.
Portable
- B.
Cheap
- C.
Relatively Simple
- D.
High Speed Execution
Correct Answer
D. High Speed Execution -
- 24.
Which of the following is NOT a Java program?
- A.
Applets
- B.
Servlets
- C.
Javascript
- D.
JavaBeans
Correct Answer
C. Javascript -
- 25.
What is the file extension of your Java source file?
- A.
.class
- B.
.java
- C.
.jar
- D.
.out
Correct Answer
B. .java -
- 26.
The Java compiler translate the Java code into ______
- A.
Bitcode
- B.
Bitecode
- C.
Bytecode
- D.
Bycode
Correct Answer
C. Bytecode -
- 27.
In order to execute a Java application, you need to have ______ on your computer
- A.
Java Virtual Machine
- B.
Java Real Machine
- C.
Java Running Machine
- D.
Java Verbal Machine
Correct Answer
A. Java Virtual Machine -
- 28.
Which of following is NOT one of the steps of program development life cycle discussed in the class?
- A.
Define the problem
- B.
Code the program
- C.
Install the program
- D.
Test and debug the program
Correct Answer
C. Install the program -
- 29.
Assembly language has one-to-one mapping to the machine language code
- A.
True
- B.
False
Correct Answer
A. True -
- 30.
Which of the following Java programs can only be run using Web browser?
- A.
Servlet
- B.
Applet
- C.
JavaBeans
- D.
EJB
Correct Answer
B. Applet -
- 31.
The Java language was developed by __________
- A.
Java Microsystem
- B.
Sun Macrosystem
- C.
Java Macrosystem
- D.
Sun Microsystem
Correct Answer
D. Sun Microsystem -
- 32.
Each Java program will have at least ___ class(es).
- A.
1
- B.
2
- C.
3
- D.
4
Correct Answer
A. 1 -
- 33.
How do you define a comment in Java code?
- A.
//
- B.
*()
- C.
/* and *//
- D.
Both a and c
Correct Answer
D. Both a and c -
- 34.
What will be the output of the program? public class X { public static void main(String [] args) { try { badMethod(); System.out.print("A"); } catch (Exception ex) { System.out.print("B"); } finally { System.out.print("C"); } System.out.print("D"); } public static void badMethod() {} }
- A.
AC
- B.
BC
- C.
ACD
- D.
ABCD
Correct Answer
C. ACD -
- 35.
Class X implements Runnable { public static void main(String args[]) { /* Missing code? */ } public void run() {} } Which of the following line of code is suitable to start a thread ?
- A.
Thread t = new Thread(X);
- B.
Thread t = new Thread(X); t.start();
- C.
X run = new X(); Thread t = new Thread(run); t.start();
- D.
Thread t = new Thread(); x.run();
Correct Answer
C. X run = new X(); Thread t = new Thread(run); t.start(); -
- 36.
public class Test { } What is the prototype of the default constructor?
- A.
Test( )
- B.
Public Test( )
- C.
Test(void)
- D.
Public Test(void)
Correct Answer
B. Public Test( ) -
- 37.
Given a method in a protected class, what access modifier do you use to restrict access to that method to only the other members of the same class?
- A.
Final
- B.
Private
- C.
Protected
- D.
Default
Correct Answer
B. Private -
- 38.
Which of the following group consists of only Object-Oriented languages?
- A.
C,C++,JAVA
- B.
C,JAVA,RUBY
- C.
C++,JAVA,BASIC
- D.
BASIC,FORTRAN,JAVA
- E.
C++,JAVA,C#
Correct Answer
E. C++,JAVA,C# -
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Current Version
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Feb 19, 2012Quiz Edited by
ProProfs Editorial Team -
Feb 19, 2012Quiz Created by
Mooly.89
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