2) What will be the output of the following program?

[code lang=”java”]
package finalize;
public class Ques01 {
public static void main(String[] args) {
MyClass object = new MyClass();
object = null;
}
}
class MyClass {
void finalize(){
System.out.println("finalize");
super.finalize();
}
}
[/code]

1. The program will output ‘finalize’.
2. It is unsure that the finalize() method will be called by the Garbage Collector.
3. As soon the object reference ‘object’ is set to null, there is a possibility that the method ‘finalize()’ will be called.
4. The program will cause compile-time errors.

Get more questions on Finalize method

Answer

2) d.

The program will cause compile-time errors and the method finalize() is declared with scope ‘protected’ in the base class and it is impossible to reduce the visibility in the derived class.

5) What will be the output of the following program?

[code lang=”java”]
package console;
public class Ques02 {
public static void main(String[] args) {
int anInt = 100;
double aDouble = 100.00;
System.console().format("%2d – %1f", anInt, aDouble);
}
}
[/code]

1. The program will output ‘100.000000 – 100’.
2. The program will output ‘100 – 100.000000’.
3. The program will throw a IllegalFormatConversionException at run-time.
4. The program will output ‘100 – 100’.

Get more questions on Console

Answer

5) b.

Here the ordering of the arguments (anInt and aDouble) matters, not the formatting strings ‘%2 – %1d’. So the first output will be the value of anInt variable followed by a hyphen (‘-‘) followed by the value of aDouble variable.

3) Which of the following statements are true about the following program?

[code lang=”java”]
package gc;
import javax.swing.JButton;
public class Ques01 {
public static void main(String[] args) {
JButton button = new JButton(); // Line A
StringBuilder sb1 = getSB(); // Line B
getSB(); // Line C
button = null; // Line D
}
static StringBuilder getSB(){
return new StringBuilder("");
}
}
[/code]

1. The button object ‘button’ will become a candidate for garbage collection as soon the execution of Line A ends since the object is not used elsewhere.
2. The newly created StringBuilder object as a result of method call in Line C becomes eligible for garbage collection.
3. Even though the object pointed by the reference ‘button’ is set to null in Line D, the garbage collector, it is unsure that the Garbage collection reclaims the memory used by ‘button’.

Get more questions on GarbageCollection

Answer

3) b and c.

The object ‘button’ wont be eligible for Garbage Collection unless it is explicitly set to null or the method returns.

NavigableMap is similar to NavigableSet. In NavigableMap we will use key value pairs to reterive the value. see the following code:

[code lang=”java”]
navigableMap.put(1,"tiger");
[/code]

Look into the following code snippet:

[code lang=”java”]
package javabeat.net;
import java.util.NavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;

public class NavigableMapExample1 {
public static void main(String args[]){
NavigableMap<Integer,String> navigableMap = new ConcurrentSkipListMap<Integer,String>();
navigableMap.put(1,"tiger");
navigableMap.put(2,"lion");
navigableMap.put(3,"leopard");
System.out.println(navigableMap.lowerEntry(2));
System.out.println(navigableMap.higherEntry(2));
}
}
[/code]

In tha bove code NavigableMap API is used for reteriving the less than and greater than value based on key. The output would be like this:

[code]
1=tiger
3=leopard
[/code]

2) What will be the output of the following program?

[code lang=”java”]
package navmap;
import java.util.HashMap;
import java.util.NavigableMap;
import java.util.TreeMap;
public class Ques01 {
public static void main(String[] args) {
NavigableMap<String, String> colors = new HashMap<String, String>();
colors.put("RED", "Red");
colors.put("BLUE", "Blue");
System.out.println(colors.get("BLUE"));
}
}
[/code]

1. The program will output ‘null’.
2. The program will return ‘Blue’.
3. The program won’t compile because of compilation errors.
4. The program will throw a run-time exception.

Get more questions on NavigableMap

Answer

2) c.

The program won’t compile since the class HashMap doesn’t implement the NavigableMap interface.

NavigableSet API is included in the ocpjp 6 certification exam. This article explains few important methods with simple example program.NavigableSet is the subinterface of SortedSet. This interface defines methods for finding the element in a list. For example lower() method used for finding the element which is less than the given value. Look into the following example:

[code lang=”java”]
package javabeat.net;

import java.util.ArrayList;
import java.util.List;
import java.util.NavigableSet;
import java.util.TreeSet;

public class NavigableSetExample1 {
public static void main(String args[]){
List<Integer> list = new ArrayList<Integer>();
list.add(3);
list.add(4);
list.add(1);
list.add(8);
list.add(7);
list.add(10);

NavigableSet navigableSet = new TreeSet(list);
System.out.println(navigableSet.lower(8));
System.out.println(navigableSet.higher(8));

}
}

[/code]

In the above code, NavigableSet.lower() method is used for reteriving the value which is less than ‘8’ in the list. Same way NavigableSet.higher() is used for reteriving the value greater than ‘8’ in the list. The output for the above program would be:

[code]
7
10
[/code]

Other than finding less than or greater than values, NavigableSet provides few more useful methods to print the values in the desired order. Look into the following code snippet:

[code lang=”java”]
package javabeat.net;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.NavigableSet;
import java.util.TreeSet;

public class NavigableSetExample2 {
public static void main(String args[]){
List<Integer> list = new ArrayList<Integer>();
list.add(4);
list.add(6);
list.add(9);
list.add(5);
NavigableSet navigableSet = new TreeSet(list);
Iterator<Integer> iterator = (Iterator)navigableSet.descendingIterator();
while (iterator.hasNext()){
Integer value = iterator.next();
System.out.println(value);
}

}
}
[/code]

Above code demonstrates how to print the values in decending order using the NaviogableSet API

4) What will be the output of the following program?

[code lang=”java”]
package navset;
import java.util.TreeSet;
public class Ques02 {
public static void main(String[] args) {
MyNavigableSet objects = new MyNavigableSet();
objects.add(new Object());
System.out.println(objects);
}
}
class MyNavigableSet extends TreeSet<String>{
public boolean add(Object value){
return super.add(value);
}
}
[/code]

1. The program will compile and run fine to print the contents of the set.
2. The program will raise a run-time exception telling that it is not possible to add objects of type ‘java.lang.Object’ in place of ‘java.lang.String’.
3. The program will raise a compile-time error.

Get more questions on NavigableSet

Answer

4) c.

A compile-time error telling that a name-clash has happened for the overridden method taking Object as argument.

Section 1: Declarations, Initialization and Scoping

• Develop code that declares classes (including abstract and all forms of nested classes), interfaces, and enums, and includes the appropriate use of package and import statements (including static imports).
• Develop code that declares an interface. Develop code that implements or extends one or more interfaces. Develop code that declares an abstract class. Develop code that extends an abstract class.
• Develop code that declares, initializes, and uses primitives, arrays, enums, and objects as static, instance, and local variables. Also, use legal identifiers for variable names.
• Develop code that declares both static and non-static methods, and – if appropriate – use method names that adhere to the JavaBeans naming standards. Also develop code that declares and uses a variable-length argument list.
• Given a code example, determine if a method is correctly overriding or overloading another method, and identify legal return values (including covariant returns), for the method.
• Given a set of classes and superclasses, develop constructors for one or more of the classes. Given a class declaration, determine if a default constructor will be created, and if so, determine the behavior of that constructor. Given a nested or non-nested class listing, write code to instantiate the class.

Section 2: Flow Control

• Develop code that implements an if or switch statement; and identify legal argument types for these statements.
• Develop code that implements all forms of loops and iterators, including the use of for, the enhanced for loop (for-each), do, while, labels, break, and continue; and explain the values taken by loop counter variables during and after loop execution.
• Develop code that makes use of assertions, and distinguish appropriate from inappropriate uses of assertions.
• Develop code that makes use of exceptions and exception handling clauses (try, catch, finally), and declares methods and overriding methods that throw exceptions.
• Recognize the effect of an exception arising at a specified point in a code fragment. Note that the exception may be a runtime exception, a checked exception, or an error.
• Recognize situations that will result in any of the following being thrown: ArrayIndexOutOfBoundsException,ClassCastException, IllegalArgumentException, IllegalStateException, NullPointerException, NumberFormatException, AssertionError, ExceptionInInitializerError, StackOverflowError or NoClassDefFoundError. Understand which of these are thrown by the virtual machine and recognize situations in which others should be thrown programatically.

Section 3: API Contents

• Develop code that uses the primitive wrapper classes (such as Boolean, Character, Double, Integer, etc.), and/or autoboxing & unboxing. Discuss the differences between the String, StringBuilder, and StringBuffer classes.
• Given a scenario involving navigating file systems, reading from files, writing to files, or interacting with the user, develop the correct solution using the following classes (sometimes in combination), from java.io: BufferedReader, BufferedWriter, File, FileReader, FileWriter, PrintWriter, and Console.
• Develop code that serializes and/or de-serializes objects using the following APIs from java.io: DataInputStream, DataOutputStream, FileInputStream, FileOutputStream, ObjectInputStream, ObjectOutputStream and Serializable.
• Use standard J2SE APIs in the java.text package to correctly format or parse dates, numbers, and currency values for a specific locale; and, given a scenario, determine the appropriate methods to use if you want to use the default locale or a specific locale. Describe the purpose and use of the java.util.Locale class.
• Write code that uses standard J2SE APIs in the java.util and java.util.regex packages to format or parse strings or streams. For strings, write code that uses the Pattern and Matcher classes and the String.split method. Recognize and use regular expression patterns for matching (limited to: . (dot), * (star), + (plus), ?, \d, \s, \w, [], ()). The use of *, +, and ? will be limited to greedy quantifiers, and the parenthesis operator will only be used as a grouping mechanism, not for capturing content during matching. For streams, write code using the Formatter and Scanner classes and the PrintWriter.format/printf methods. Recognize and use formatting parameters (limited to: %b, %c, %d, %f, %s) in format strings.

Section 4: Concurrency

• Write code to define, instantiate, and start new threads using both java.lang.Thread and java.lang.Runnable.
• Recognize the states in which a thread can exist, and identify ways in which a thread can transition from one state to another.
• Given a scenario, write code that makes appropriate use of object locking to protect static or instance variables from concurrent access problems.
• Given a scenario, write code that makes appropriate use of wait, notify, or notifyAll.

Section 5: OO Concepts

• Develop code that implements tight encapsulation, loose coupling, and high cohesion in classes, and describe the benefits.
• Given a scenario, develop code that demonstrates the use of polymorphism. Further, determine when casting will be necessary and recognize compiler vs. runtime errors related to object reference casting.
• Explain the effect of modifiers on inheritance with respect to constructors, instance or static variables, and instance or static methods.
• Given a scenario, develop code that declares and/or invokes overloaded methods and code that declares and/or invokes superclass, or overloaded constructors.
• Develop code that implements “is-a” and/or “has-a” relationships.

Section 6: Collections / Generics

• Given a design scenario, determine which collection classes and/or interfaces should be used to properly implement that design, including the use of the Comparable interface.
• Distinguish between correct and incorrect overrides of corresponding hashCode and equals methods, and explain the difference between == and the equals method.
• Write code that uses the generic versions of the Collections API, in particular, the Set, List, and Map interfaces and implementation classes. Recognize the limitations of the non-generic Collections API and how to refactor code to use the generic versions. Write code that uses the NavigableSet and NavigableMap interfaces.
• Develop code that makes proper use of type parameters in class/interface declarations, instance variables, method arguments, and return types; and write generic methods or methods that make use of wildcard types and understand the similarities and differences between these two approaches.
• Use capabilities in the java.util package to write code to manipulate a list by sorting, performing a binary search, or converting the list to an array. Use capabilities in the java.util package to write code to manipulate an array by sorting, performing a binary search, or converting the array to a list. Use the java.util.Comparator and java.lang.Comparable interfaces to affect the sorting of lists and arrays. Furthermore, recognize the effect of the “natural ordering” of primitive wrapper classes and java.lang.String on sorting.

Section 7: Fundamentals

• Given a code example and a scenario, write code that uses the appropriate access modifiers, package declarations, and import statements to interact with (through access or inheritance) the code in the example.
• Given an example of a class and a command-line, determine the expected runtime behavior.
• Determine the effect upon object references and primitive values when they are passed into methods that perform assignments or other modifying operations on the parameters.
• Given a code example, recognize the point at which an object becomes eligible for garbage collection, determine what is and is not guaranteed by the garbage collection system, and recognize the behaviors of the Object.finalize() method.
• Given the fully-qualified name of a class that is deployed inside and/or outside a JAR file, construct the appropriate directory structure for that class. Given a code example and a classpath, determine whether the classpath will allow the code to compile successfully.
• Write code that correctly applies the appropriate operators including assignment operators (limited to: =, +=, -=), arithmetic operators (limited to: +, -, *, /, %, ++, –), relational operators (limited to: <, <=, >, >=, ==, !=), the instanceof operator, logical operators (limited to: &, |, ^, !, &&, ||), and the conditional operator ( ? : ), to produce a desired result. Write code that determines the equality of two objects or two primitives.

The Oracle Certified Professional for Java Platform, Standard Edition 6 certification exam is for programmers experienced using the Java programming language. Achieving this certification provides clear evidence that a programmer understands the basic syntax and structure of the Java programming language and can create Java technology applications that run on server and desktop systems using Java SE 6.

OCPJP 6 / SCJP 6 New Mock Exams

• NavigableSet
• NavigableMap
• Garbage Collection
• Console API
• Finalize Method

What is new in OCPJP 6 / SCJP 6?

There is few minor changes from the previous version 5.0. Objectives are very similar to SCJP 5.0 exam except that few minor updates. In the following section bolded topics are updated in OCPJP 6.

• Section : 3

1.6: Given a scenario involving navigating file systems, reading from files, writing to files, or interacting with the user, develop the correct solution using the following classes (sometimes in combination), from java.io: BufferedReader, BufferedWriter, File, FileReader, FileWriter, PrintWriter, and Console ( mock exams for console ).

• Section : 5

1.5: Given a scenario, develop code that declares and/or invokes overridden or overloaded methods and code that declares and/or invokes superclass or overloaded constructors.

• Section : 6

1.6: Write code that uses the generic versions of the Collections API, in particular, the Set, List, and Map interfaces and implementation classes. Recognize the limitations of the non-generic Collections API and how to refactor code to use the generic versions. Write code that uses the NavigableSet  and NavigableMap  interfaces.

• Section : 7

1.5: Given a code example, recognize the point at which an object becomes eligible for garbage collection, and determine what is and is not guaranteed by the garbage collection system. Recognize the behaviors of System.gc and finalization ( mock exams for garbage collection in ocpjp 6 ).

1.6: Given a code example, recognize the point at which an object becomes eligible for garbage collection, determine what is and is not guaranteed by the garbage collection system, and recognize the behaviors of the Object.finalize() method.

SCJP Practice Questions

• Mock Exam 1
• Mock Exam 2
• Mock Exam 3
• Mock Exam 4
• Mock Exam 5
• Mock Exam 6
• Mock Exam 7
• Mock Exam 8
• Mock Exam 9
• Mock Exam 10
• Mock Exam 11
• Mock Exam 12
• Mock Exam 13
• Mock Exam 14
• Mock Exam 15
• Mock Exam 16
• Mock Exam 17
• Mock Exam 19
• Mock Exam 20
• Mock Exam 21

 

OCPJP / SCJP FAQs

This section provides details for the beginner of Sun certification exams. Who doesn’t have any knowledge on Sun certifications can read this section to get basic knowledge about the various sun certifications and procedures to appear for the exams.

what is SCJP exam?

SCJP stands for Sun Certified Java Programmer. This certification is given by Sun Micro Systems, creator of Java technologies. This is the prelim exam in the series of Java technologies certification, to asess the basic knowledge in core java.

who is conducting the exam?

Sun Micro Systems Inc. (Sun’s official site)

Are there any pre-requisites for appearing for the SCJP exam?

There is no pre-requisite to appear for the exam, other than knowing Java language concepts and syntax thoroughly.

What type of questions are asked in the test?

You will find three types of questions on this examination:

• Multiple-Choice Questions with a Single-Correct Answer
• Multiple-Choice Questions with Multiple-Correct Answers
• Fill-In Questions Requiring your Typed Response

What will I get after I pass the Certification?

Candidates passing the exam will receive a temporary certificate before leaving the examination center. It will have your pass/fail grade, score, and feedback on your performance by categories or objectives. Once the results are uploaded to the SUN’s central database, a permanent certificate is dispatched to the candidate.

Will the certificate contain my score and number of attempts?

The certificate will not have any of the above.

How do I register for the exam?

Obtain an exam voucher from Sun Educational Services. Once you obtain the voucher, it can then be redeemed by signing up for the test at Prometric which is done by making an appointment for specific date and time. The voucher cannot be refunded back for your money, but it can be transferred.

What to do if I need to reschedule my test?

If you should need to cancel or reschedule your exam, you must contact Prometric one business day prior to your test date or you will lose your testing fee.

1 . Given:

[code]
AnInterface is an interface.
AnAdapter0 is a non-abstract, non-final class with a zero argument constructor.
An Adapterl is a non-abstract, non-final class without a zero argument constructor, but with a
constructor that takes one int argument.
[/code]

Which two construct an anonymous inner class?

Choose the two below:

1. AnAdapter1 aa = new AnAdapter1 () {}
2. AnAdapter0 aa = new AnAdapter0 () {}
3. AnAdapter0 aa = new AnAdapter0 (5) {}
4. AnAdapter1 aa = new AnAdapter1 (5) {}
5. AnInterface ai = new Anlnterface (5)) {

2 . What will be the output?

[code lang=”java”]
class A {
public String to String() {
return ?4?;
}
}
class B extends A {
public String toString() {
return super.toString() + ?3?;
}
}
public class Test {
public static void main (String[] args) {
System.out.printIn(new B());
}
}
[/code]

Choose the one below:

1. Compilation succeeds and 4 is printed
2. Compilation ????? is printed
3. An error on line 9 cause compilation to fail
4. An error on line 14 cause compilation to fail
5. Compilation succeeds but an exception is thrown at line 9

3 . What will be the output?

[code lang=”java”]
public class Method Over {
public void set Var (int a, int b, float c) {
}
}
[/code]

Choose the two below:

1. private void set Var(int a, float c, int b) {}
2. protected void set Var(int a, int b, float c) {}
3. public int set Var(int a, float c, int b) {return a}
4. public int set Var(int a, int b, float c) {return a}
5. protected float set Var(int a, int b, float c) {return c}

4 . What will be the output?

[code lang=”java”]
class A {
public byte file Number () {
return l;
}
}

Class B extends A {
public short getNumber() {
return 2;
}

public short getNumber() {
B b = new B();
System.out.printIn(b.getNumber());
}
}
[/code]

Choose the one below:

1. Compilation succeeds and l is printed
2. Compilation succeeds and 2 printed
3. An error at line 8 cause compilation to fail
4. An error at line 14 cause complication to fail
5. Complication succeeds but an exception is thrown at line 14

5 . What will be the output?

[code lang=”java”]
public class Foo {
public static void main(String[] args) {
StringBuffer a = new StringBuffer(?A?);
StrinbBuffer b = new StringBuffer(?B?);
operate (a, b);
System.out.printIn(a + ?,? + b)
}
static void operate (StringBuffer x, StringBuffer y) {
y.append(x);
y = x;
}
}
[/code]

Choose the one below:

1. The code compiles and prints ?A,B?
2. The code compiles and prints ?A,BA?
3. The code compiles and prints ?AB,B?
4. The code compiles and prints ?AB,AB?
5. The code compiles and prints ?BA,BA?
6. The code does not compile because ?+? cannot be overloaded for StringBuffer

6 . What will be the output?

[code lang=”java”]
public class X {
private static int a

public static void main (String [] args) {
modify (a)
System.out.printIn(a) {
}

public static void modify (int a) {
a++;
}
}
[/code]

Choose the one below:

1. The program runs and prints ?0?
2. The program runs and prints ?1?
3. The program runs but aborts with an exception
4. An error ?possible undefined variable? at line 5 cause compilation to fail
5. An error ?possible undefined variable? at line 10 cause compilation to fail

7 . What will be the output?

[code lang=”java”]
public class Test {
private static int j = 0;

public static Boolean method B (int k) {
j + = k;
return true
}

public static void method A (int i) {
Boolean b;
b = I < 10 | method b (4)
b = I < 10 || method b(8)
}

public static void main (String args []) {
method A (0);
System.out.printIn(i);
}
}
[/code]

Choose the one below:

1. The program prints ?0?
2. The program prints ?4?
3. The program prints ?8?
4. The program prints ?12?
5. The code does not compile

8 . Which two are equivalent?

1. 16 > 4
2. 16 / 2
3. 16 * 4
4. 16 >> 2
5. 16 / 22
6. 16 >>> 2

9 . What will be the output?

[code lang=”java”]
public class X {
public static void main (String [] args) {
byte b = 1277;
byte c = 126;
byte d = b + C;
}
}
[/code]

Choose the one below:

1. Compilation succeed and d take the value 253
2. Line 5 contains an error that prevents compilation
3. Line 5 throws an exception indicating ?out of range?
4. Line 3 and 4 contain errors that prevent compilation
5. The compilation succeed and d takes the value of 1

10 . What will be the output?

[code lang=”java”]
int index = 1;
int[]foo = new int [3];
int bar = foo [index];
int baz = bar + index;
[/code]

Choose the one below:

1. baz has a value of 0
2. baz has a value of 1
3. baz has the value of 2
4. An exception is thrown
5. The code will not compile

Answers

1 : 2 & 4 is correct.

2 : 2 is correct.

3 : 1 & 3 is correct.

4 : 3 is correct.

5 : 2 is correct.

6 : 1 is correct.

7 : 2 is correct.

8 : 4 & 6 is correct.

9 : 2 is correct.

10 : 2 is correct.

1 . Which of the following are valid array construction?

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

2 . Which of the following are valid array initialization?

1. new int[] = {1,2,3,4};
2. new int[10] = {1,2,3,4};
3. new int[] = 1,2,3,4;
4. new int[] = [1,2,3,4];

3 . What will be the output?

[code lang=”java”]
public class Test3{
public static void main(String args[]){
int arr[] = new int[10];
int i = 5;
arr[i++] = ++i+i++;
System.out.print(arr[5]+":"+arr[6]);
}
}
[/code]

Choose the one below:

1. 14:0
2. 0:14
3. 0:0
4. Compiler Error

4 . What will be the output?

[code lang=”java”]
public class Test4{
public static void main(String args[]){
int arr[] = new int[10];
int i = 5;
arr[i++] = i+++i++;
System.out.print(arr[5]+":"+arr[6]);
}
}
[/code]

Choose the one below:

1. 13:0
2. 14:0
3. 0:14
4. 0:13

5 . What will be the output?

[code lang=”java”]
public class Test5{
static Boolean bl[] = new Boolean[5];
public static void main(String args[]){
System.out.println(bl[0]);
}
}
[/code]

Choose the one below:

1. Null
2. False
3. True
4. Compiler Error

6 . Which of the following are valid array declarations?

1. String[][] a1 = String[20][20];
2. String[][] a2 = new String[20,20];
3. String[][] a3 = new String[20][20];
4. String a4[][] = new String[20][20];
5. String[] a5[] = new String[20][20];

7 . Which of the following code correctly creates an array of four initialized string objects?

1. String players[] = new String[4];
2. String players[] = {“”,””,””,””};
3. String players[];
4. players = new String[4];
5. None of the above

8 . What will be the output?

[code lang=”java”]
char[] c = new char[100];
[/code]

what is the value of c[50]?

Choose the one below:

1. 50
2. 49
3. ‘\u0000’
4. ‘\u0020’

9 . which of the following are valid arrays?

1. new float[10]={1,2};
2. new float[]={1,2};
3. new float={1,2};
4. None of the above

10 . What will be the output?

[code lang=”java”]
public class Test10{
public void method(int arr[]){
arr[0] = 10;
}
public static void main(String[] args){
int[] small = {1,2,3};
Test10 t= new Test10();
t.method(small);
System.out.println(small[0]);
}
}
[/code]

Choose the one below:

1. 0
2. 1
3. 0
4. None of the above

Answers

1 : 2 is correct. int a[] = new int[10];

2 : 1 is correct. new int[] = {1,2,3,4};

3 : 1 is correct. 14:0

4 : 1 is correct. 13:0

5 : 1 is correct. Null.

6 : 3,4 & 5 is correct.
3 . String[][] a3 = new String[20][20];
4 . String a4[][] = new String[20][20];
5 . String[] a5[] = new String[20][20];

7 : 2 is correct. String players[] = {“”,””,””,””};

8 : 3 is correct. ‘\u0000’

9 : 2 is correct. new float[]={1,2};

10 : 10.

1 . What will be the output?

[code lang=”java”]
public class Test1{
private static int i = 10;
static class Inner extends Test1{
int i;
public void method(){
System.out.println(i);
}
}
public static void main(String args[]){
new Test10.Inner().method();
}
}
[/code]

Choose the one below:

1. 10
2. 0
3. Nothing is printed
4. Compiler error

2 . which of the following modifiers are applied to the nested classes class?

1. private
2. protected
3. public
4. static
5. All the above

3 . which of the following modifiers are applied to the top level classes?

1. static
2. private
3. strictfp
4. abstract
5. All the above

4 . which modifer is uesd to stop overridding a method?

1. final
2. static
3. abstract
4. None of the above

5 . What will be the output?

[code lang=”java”]
public abstract final class Test5{
public static void main(String args[]){
System.out.println("Modifiers");
}
}
[/code]

Choose the one below:

1. Modifiers
2. Compiler error
3. Exception thrown at runtime
4. None of the above

6 . which of the following are valid syntax for a toplevel class?

1. public static class Test6{}
2. public abstrct class Test6{}
3. private final class Test6{}
4. public final class Test6{}

7 . which of the following are valid syntax for nested classes?

1. private final abstract class Test7{}
2. private final class Test7{}
3. private static class Test7{}
4. protected abstract class Test7{}

8 . What will be the output?

[code lang=”java”]
public class Test8{
class Inner{
public void method(){
System.out.println("Inner class");
}
}
public static void main(String args[]){
// ?
}
}
[/code]

Choose the one below:

1. new Test8.Inner().method();
2. new Test8().Inner().method();
3. new Test8.Inner.method();
4. Compiler error

9 . What will be the output?

[code lang=”java”]
public class Test9{
static class Inner{
public void method(){
System.out.println("Inner class");
}
}
public static void main(String args[]){
// ?
}
}
[/code]

Choose the one below:

1. new Test9.Inner().method();
2. new Test9().Inner().method();
3. new Test9.Inner.method();
4. Compiler error

10 . which of the following modifiers are applied to local classes(classses inside method)?

1. private
2. public
3. protected
4. None of the above

Answers

1 : 3 is correct.

2 : 5 is correct. All the above.

3 : 3 & 4 is correct.
3 . strictfp
4 . abstract

4 : 1 is correct. final.

5 : 2 is correct. Compiler error.

6 : 2 & 4 is correct.
2 . public abstrct class Test6{}
4 . public final class Test6{}

7 : 2,3 & 4 is correct.
2 . private final class Test7{}
3 . private static class Test7{}
4 . protected abstract class Test7{}

8 : 4 is correct. Compiler error.

9 : 1 is correct. new Test9.Inner().method();.

10 : 4 is correct. None of the above.