Test Your Java 7 and Test Your Java 8 are advanced questions. Answers are given for each question at the end of each test. Answering these questions increases your knowledge in Java and helps you a lot when you appear for interviews. Solving these basic questions is your first step for Certification Exams preparation.
Test Your Java 3
- Arrays in Java work differently than what they do in C/C++.
a) True b) False - Arrays are
a) objects b) object references c) primitive data types d) none - char[] c = new char();
char[] c = new char(4);
char[] c = new char[];
All the above three statements are invalid.
a) True b) False - int[] intarray1 = new int[] { 10, 20 };
int[] intarray2 = { 10, 20 };We can form an array in the either way of the above statements.
a) True b) False - int intarray[3] = { 10, 20, 30 };
System.out.println(intarray[1]);
The fraction of code outputs 20.
a) True b) False - It is possible to change the size of the array once it is created.
a) True b) False - .
public class ZeroValue { public static void main(String args[]) { Integer x[] = new Integer[3]; System.out.println(x[0]); } }
what is the output of the above println statement?
a) 0 b) 1 c) null d) does not compile e) throws exception - int rates[] = {10, 20, 30 };
System.out.println(rates.length());
What is the output of the above fragment of code?
a) 0 b) 2 c) 3 d) does not compile e) throws exception f) none - .
class ArrayArgument { void display(int arrays[]) { System.out.println(arrays[0] += 2); } public static void main(String args[]) { int intarray[] = { 5, 10, 15 }; ArrayArgument arrarg = new ArrayArgument(); arrarg.display(intarray); System.out.println(intarray[0]); } }
The above program
a) both println statements prints the same value 7. b) one println prints 7 and the other 5 c) does not compile. d) compiles but throws an exception e) none - Java, like C/C++, treates text string as an array of characters.
a) True b) False - String s1 = "RAMA\nKRISHNA";
System.out.println(s1);
The above fraction code prints the output in two different lines.
a) True b) False - String s1 = new String("Hello");
String s2 = new String("Hellow");
System.out.println(s1 = s2);
The output of the above fraction of code is
a) Hello b) Hellow c) does not compile d) throws an exception e) none - .
class LogicalCompare { public static void main(String args[]) { String str1 = new String("OKAY"); String str2 = new String(str1); System.out.println(str1 == str2); } }
What is the output of the above program?
a) displays error message b) true c) false d) 0 e) 1 f ) none - String s1 = "java";
String s2 = "java";
System.out.println(s1.equals(s2));
System.out.println(s1 == s2);
Both the above println statements returns true.
a) True b) False - String s1 = "SITHA" ;
String s2 = "RAMA";
System.out.println(s1.charAt(0) > s2.charAt(0));
What is the output of the above code ?
a) True b) False c) 0 d) does not compile e) throws exception f)none - stringWidth() method is defined in _______________ class.
a) String b) AWT c) Font d) FontMetrics e) none - String x = "hellow";
int y = 9;
System.out.println(x += y);
What could be output of the above fragment of code?
a) does not compile b) throws an exception as string and int are not compatible for addition c) hellow9 d) 9hellow e) none - toString() method is defined in
a) java.lang.String b) java.lang.Object c) java.lang.util d) none - "Toolbar".startsWith("bar", 4);
The above statement returns
a) False b) True c) does not return any thing d) displays error message e) none - The String method compareTo() returns
a) True b) False c) int value d) 1 e) -1 f) none - String str1 = "abcde";
System.out.println(str1.substring(1, 3));
The above program prints bc.
a) True b) False - String str1 = "Hellow";
System.out.println(str1.indexOf('t'));
What is the output of the above println statement
a) True b) False c) 1 d) -1 e) 0 f) displays error message g) none - .
class ConcatEqual { public static void main (String args[]) { String str1 = "one";; String str2 = "two"; System.out.println(str1.concat(str2).equals(str1 + str2)); } }
a) 0 b) 1 c) no output d) -1 e) True f) False g) displays error message h) none
- String str1 = "Helloww".replace('l', 'w');
In the above statement, the effect on string Helloww is
a) the last occurrence of character w is replaced by l b) the first occurrence of l is replaced by w. c) all characters l are replaced by w.
d) all characters w are replaced by l. e) displays error message
f) the first occurrence of w is replaced by l. g) none - char ch = 'x';
System.out.println(String.valueOf(ch));
What could be output of the above fragment of code ?
a) Unicode value of character x. b) x c) displays error message d) none
ANSWERS
1. a | 2. a | 3. a | 4. a | 5. b |
6. b | 7. c | 8. d | 9. a | 10. b |
11. a | 12. b | 13. c | 14. a | 15. a |
16. d | 17. c | 18. b | 19. b | 20. c |
21. a | 22. d | 23. e | 24. c | 25. b |
Correct Answers |
---|
1 to 5 : Poor |
6 t0 10: Below average |
11 t0 15: Average |
16 to 20: Good |
Above 20: Extraordinary |
Pass your comments and suggestions for the improvement of this "Test Your Java 3".
Sir can you please explain why 9th answer will be option a and not option b?
In Java objects are passed by reference. Array objects intarray and arrays point to the same location of values. If one object changes their values, other also gets effected.
The num 22 can not compile. It need another “)”
String str1 = “Hellow”;
System.out.println(str1.indexOf(‘t’); – See more at: http://way2java.com/java-questions/test-your-java-3/#sthash.MbCECGMp.dpuf
Yes, corrected. Thank you.
Dear Sir,
Can you please explain me Why a protected instance variable of super class in one package cannot be accessed by an object of super class inside the sub class in a different package?
http://way2java.com/oops-concepts/specifiers-modifiers/access-specifier-vs-access-modifier-in-java/
Dear sir,
Can you pls explain me how the float value gets appended in the string?
String x = “hellow”;
float y = 9.0f;
System.out.println(x =x+ y);
I thought it would cause an error…
It uses StringBuffer append() method internally.
for question 11 the right ans is option b
Just type the println() statement in a main() and check. It gives output in two line. For this reason, \n is known as escape sequence which escapes normal sequence of execution.
Sir!
Q)what is need of Desirization? when to go for?
Serialized data cannot be interpreted by a processor. It must be converted back into the original format. This is deserialization.
Sir!
Q)how to add jar files dynamically in classpath?
If it is Eclipse IDE, through Buildpath – external Jars. Else, like c:\snr\abc.jar
Sir!
Q) i am put 3+ exp on java.. if go any interview they asked project flow? how to explian? i am not genuine guy? or give me any idea how to escape?
Take the help of a real guy; only he can bail out.
Sir!
Q)how to find a class is Serialized or not?
Open the API and see the class signature.
Sir!
Q)Diff. b/w Servlet Outext and Servlet Outing?
ServletContext object data can be shared by all the servlets ad where as ServletConfig is meant for a single servlet.
Sir!
Q)how listener will identify port no?
This is taken care by the underlying OS.
Hi,
QNo: 23 is giving compilation error. but, in the answers it was mentioned TRUE.
which Test paper. Pl write the number.
Test Your Java 3, QNo: 23 is giving compilation error. but, in the answers it was mentioned TRUE.
Now corrected. It was html to java conversion problem. Thank you.