1. Select all correct declarations, or declaration and initializations of an array?
A) String str[];
B) String str[5] = new String[5];
C) String str[]=new String [] {"string1", "string 2", "string3", "string4", "string5"};
D) String str[]= {"string1","string2", "string3", "string4", "string5"};
2. Which of the following are the java keywords?
A) final
B) Abstract
C) Long
D) static
3. The synchronized is used in which of the following?
A) Class declarations.
B) Method declarations.
C) Block of code declarations
D) Variable declarations.
4. What will be printed when you execute the code?
class A {
A() {
System.out.println("Class A Constructor");
}
}
public class B extends A {
B() {
System.out.println("Class B Constructor");
}
public static void main(String args[]) {
B b = new B();
}
}
A) "Class A Constructor" followed by "Class B Constructor"
B) "Class B Constructor" followed by "Class A Constructor"
C) Compile time error
D) Run time error
5. Given the piece of code, select the correct to replace at the comment line?
class A {
A(int i) { }
}
public class B extends A {
B() {
// xxxxx
}
public static void main(String args[]) {
B b = new B();
}
}
A) super(100);
B) this(100);
C) super();
D) this();
6. Which of the statements are true?
A) Overridden methods have the same method name and signature
B) Overloaded methods have the same method name and signature
C) Overridden methods have the same method name and different signature
D) Overloaded methods have the same method name and different signature
7. What is the output when you execute the following code?
int i = 100;
switch (i) {
case 100:
System.out.println(i);
case 200:
System.out.println(i);
case 300:
System.out.println(i);
}
A) Nothing is printed
B) Compile time error
C) The values 100,100,100 printed
D) Only 100 is printed
8. How can you change the break statement below so that it breaks out of the inner and middle loops and continues with the next iteration of the outer loop?
outer: for ( int x =0; x < 3; x++ ) {
middle: for ( int y=0; y < 3; y++ ) {
if ( y == 1) {
break;
}
}
}
A) break inner:
B) break middle:
C) break outer:
D) continue
E) continue middle
9. What is the result of compiling the following code?
import java.io.*;
class MyExp {
void MyMethod() throws IOException, EOFException {
//............//
}
}
class MyExp1 extends MyExp {
void MyMethod() {
//..........//
}
}
public class MyExp2 extends MyExp1 {
void MyMethod() throws IOException {
//.........//
}
}
A) Compile time error
B) No compile time error
C) Run-Time error
D) MyMethod() cannot throw an exception in MyExp2 class
10. What is the result when you compile the and run the following code?
public class ThrowsDemo {
static void throwMethod() {
System.out.println("Inside throwMethod.");
throw new IllegalAccessException("demo");
}
public static void main(String args[]) {
try {
throwMethod();
} catch (IllegalAccessException e) {
System.out.println("Caught " + e);
}
}
}
A) Compilation error
B) Runtime error
C) Compile successfully, nothing is printed.
D) inside demoMethod. followed by caught: java.lang.IllegalAccessExcption: demo
11. Which statements about garbage collection are true?
A) The garbage collector runs in low memory situations
B) You can run the garbage collector when ever you want.
C) When it runs, it releases the memory allocated by an object.
D) Garbage collector immediately runs when you set the references to null.
12. From the following code how many objects are garbage collected?
String string1 = "Test";
String string2 = "Today";
string1 = null;
string1 = string2;
A) 1
B) 2
C) 3
D) 0
13. Select all correct list of keywords?
A) superclass
B) goto
C) open
D) integer
E) import, package
F) They are all java keywords
14. Select the correct form for anonymous inner class declaration ?
A) new Outer.new Inner
B) new Inner() {
C) new Inner()
D) Outer.new Inner()
15. Which of the following statements are true?
A) An anonymous class cannot have any constructors
B) An anonymous class can only be created within the body of a method
C) An anonymous class can only access static fields of the enclosing class
D) An anonymous class instantiated and declared in the same place.
16. Which of the following class definitions are legal declaration of an abstract class?
A) class A { abstract void Method() {} }
B) abstract class A { abstract void Method() ; }
C) class A { abstract void Method() {System.out.println("Test");} }
D) class abstract A { abstract void Method() {} }
17. What is the result of compiling the following code?
public class Test {
public static void main ( String[] args) {
int value;
value = value + 1;
System.out.println(" The value is : " + value);
}
}
A) Compile and runs with no output
B) Compiles and runs printing out "The value is 1"
C) Does not compile
D) Compiles but generates run time error
18. What is the result of compiling the following code? When you run like given below?
java Test Hello How Are You
public class Test {
public static void main ( String[] args) {
for ( int i = 0; i < args.length; i++)
System.out.print(args[i]);
}
}
A) Compile and runs with no output
B) Compiles and runs printing out "HelloHowAreYou"
C) Does not compile
D) Compiles but generates run time error
19. Which are the following are java keywords ?
A) goto
B) synchronized
C) extends
D) implements
E) this
F) NULL
20. What is the output of the following code?
public class TestLocal {
public static void main(String args[]) {
String s[] = new String[6];
System.out.print(s[6]);
}
}
A) A null is printed
B) Compile time error
C) Exception is thrown
D) null followed by 0 is printed on the screen
21. Which of the following assignment statements is invalid?
A) long l = 698.65;
B) float f = 55.8;
C) double d = 0x45876;
D) All of the above
22. What is the numeric range for a Java int data type?
A) 0 to (2^32)
B) -(2^31) to (2^31)
C) -(2^31) to (2^31 - 1)
D) -(2^15) to (2^15 - 1)
23. How to represent number 7 as hexadecimal literal?
-----------
24. ------- is the range of the char data type?
25. Which of the following method returns the ID of an event?
A) int getID()
B) String getSource()
C) int returnID()
D) int eventID()
26. Which of the following are correct, if you compile the following code?
public class CloseWindow extends Frame implements WindowListener {
public CloseWindow() {
addWindowListener(this); // This is listener registration
setSize(300, 300);
setVisible(true);
}
public void windowClosing(WindowEvent e) {
System.exit(0);
}
public static void main(String args[]) {
CloseWindow CW = new CloseWindow();
}
}
A) Compile time error
B) Run time error
C) Code compiles but Frames does not listen to WindowEvents
D) Compile and runs successfully.
27. What is correct about event handling in Java?
A) Java 1.0 event handling is compatible with event delegation model in Java 1.1
B) Java 1.0 and Java 1.1 event handling models are not compatible
C) Event listeners are the objects that implements listener interfaces.
D) You can add multiple listeners to any event source, then there is no guarantee that the listeners will be notified in the order in which they were added.
28. Given the byte with a value of 01110111, which of the following statements will produce 00111011?
A) 0x77 << 1;
B) 0x77 >>> 1;
C) 0x77 >> 1;
D) None of the above
29. Which of the following will compile without error?
A) char c = 'a';
B) double d = 45.6;
C) int i = d;
D) int k = 8;
30. Which of the following returns true when replace with XXXXXXXXX?
public class TestType {
public static void main(String args[] ) {
Button b = new Button("BUTTON");
if( XXXXXXXXX) {
System.out.print("This is an instance of Button");
}
}
}
A) b instanceof Button
B) Button instanceof b
C) b == Button
D) Button == (Object) b
31. The statement X %= 5, can best described as?
A) A equals a divided by 5;
B) A equals A in 5 digit percentage form
C) A equals A modulus 5.
D) None of the above
32. What will happen when you attempt to compile and run the following code?
public class MyClass {
public static void main(String args[]) {
String s1 = new String("Test One");
String s2 = new String("Test One");
if ( s1== s2 ) {
System.out.println("Both are equal");
}
Boolean b = new Boolean(true);
Boolean b1 = new Boolean(false);
if ( b.equals(b1) ) {
System.out.println("These wrappers are equal");
}
}
}
A) Compile time error
B) Runtime error.
C) No output
D) "These wrappers are equal"
33. What is the result when you try to compile the following code?
public class TestBit {
public static void main(String args[]) {
String s = "HelloWorld";
if ((s != null) && (s.length() > 6))
System.out.println("The value of s is " + s );
}
}
A) Compile time error
B) Runtime error
C) No output is printed
D) "The value of s is HelloWorld" is printed on the screen
34. Given the following declaration which of the following statements equals to true
boolean b1 = true;
boolean b2 = false;
A) b1 == b2;
B) b1 || b2;
C) b1 |& b2;
D) b1 && b2;
35. What is the result of the following code?
public class MyTest {
int x = 30;
public static void main(String args[]) {
int x = 20;
MyTest ta = new MyTest();
ta.Method(x);
System.out.println(" The x value is " + x);
}
void Method(int y){
int x = y * y;
}
}
A) "The x value is 20.
B) "The x value is 30.
C) "The x value is 400.
D) "The x value is 600.
36. How can you implement encapsulation.
A) By making methods private and variable private
B) By making methods are public and variables as private
C) Make all variable are public and access them using methods
D) Making all methods and variables as protected.
37. Given the following class definition, which of the following methods could be legally placed after the comment ?
public class Test{
public void amethod(int i, String s){}
//Here
}
A) public void amethod(String s, int i){}
B) public int amethod(int i, String s){}
C) public void amethod(int i, String mystring){}
D) public void Amethod(int i, String s) {}
38. Given the following class definition which of the following can be legally placed after the comment line?
class Base{
public Base(int i){}
}
public class Derived extends Base{
public static void main(String arg[]){
Derived d = new Derived(10);
}
Derived(int i){
super(i);
}
Derived(String s, int i){
this(i);
//Here
}
}
A) Derived d = new Derived();
B) super();
C) this("Hello",10);
D) Base b = new Base(10);
39. Which of the following statements are true?
A) An anonymous inner class cannot have any constructors
B) An anonymous inner class can created only inside a method.
C) An anonymous inner class can only access static fields of the enclosing class
D) An anonymous inner class can implement an interface
40. What does the following code does?
public class R Thread implements Runnable {
public void run (String s ) {
System.out.println ("Executing Runnable Interface Thread");
}
public static void main ( String args []) {
RThread rt = new RThread ( );
Thread t = new Thread (rt);
t.start ( );
}
}
A) The compiler error
B) The runtime error
C) Compiles and prints "Executing Runnable Interface Thread" on the screen
D) Compiles and does not print any thing on the screen
41. Which statements are true?
A) Threads start() method automatically calls run() method .
B) Thread dies after the run() returns
C) A dead Thread can be started again.
D) A stop() method kills the currently running Thread
42. The ThreadGroup class instance?
A) Allow threads to be manipulated as group
B) Provide support for ThreadDeath listeners
C) May contain other ThreadGroups
D) Must contain threads of the same type.
43. Default Layout Managers are concerned ?
A) Frame's default Layout Manager is Border
B) Applet's is FlowLayout
C) Panel's is FlowLayout
D) A Dialog is a pop up window and used as BorderLayout as default.
44. Which statements are true about GridBagLayout ?
A) Weight x and weight y should be 0.0 and 1.0
B) If fill is both, anchor does not make sense.
C) It divides its territory in to an array of cells.
D) While constructing GridBagLayout , you won't tell how many rows and columns the underlying grid has.
45. Which of the following are true?
A) gridwidth, gridheight, specifies how many columns and rows to span.
B) gridx, gridy has GridBagConstraints.RELATIVE which adds left to right and top to bottom, still you can specify gridwidth and gridheight except for last component, which you have to set GridBagConstraints.REMAINDER.
46. Which of the following statements are true about the fragment below?
import java.lang.Math;
public class Test {
public static void main(String args[]) {
Math m = new Math();
System.out.println(m.abs(2.6);
}
}
A) Compiler fails at line 1
B) Compiler fails at line 2
C) Compiler fails at the time of Math class instantiation
D) Compiler succeeds.
47. What will be the output of the following line?
public class TestFC {
public static void main(String args[]) {
System.out.println(Math.floor(145.1));
System.out.println(Math.ceil(-145.4));
}
}
A) 145.0 followed by -145.0
B) 150.0 followed by -150.0
C) 145.1 followed by -145.4
48. Which of the following prints "Equal"
A) int a = 10; float f = 10;
if ( a = = f) { System.out.println("Equal");}
B) Integer i = new Integer(10);
Double d = new Double(10);
if ( i = =d) { System.out.println("Equal");}
C) Integer a = new Integer(10);
int b = 10;
if ( a = = b) { System.out.println("Equal");}
D) String a = new String("10");
String b = new String("10");
if ( a = = b) { System.out.println("Equal");}
49. Which of the following implement clear notion of one item follows another (order)?
A) List
B) Set
C) Map
D) Iterator
50. Collection interface iterator method returns Iterator(like Enumerator), through you can traverse a collection from start to finish and safely remove elements.
A) true
B) false
51. Which of the following places no constraints on the type of elements, order of elements, or repetition of elements with in the collection.?
A) Collection
B) collection
C) Map
D) Set
52. Which of the following gives Stack and Queue functionality.?
A) Map
B) Collection
C) List
D) Set
53. If you run the following code on a PC from the directory c:\source:
import java.io.*;
class Path {
public static void main(String[] args) throws Exception {
File file = new File("Ran.test");
System.out.println(file.getAbsolutePath());
}
}
What do you expect the output to be? Select the one right answer.
A) Ran.test
B) source\Ran.test
C) c:\source\Ran.test
D) c:\source
E) null
54. Which of the following will compile without error?
A) File f = new File("/","autoexec.bat");
B) DataInputStream d = new DataInputStream(System.in);
C) OutputStreamWriter o = new OutputStreamWriter(System.out);
D) RandomAccessFile r = new RandomAccessFile("OutFile");
55. You have an 8-bit file using the character set defined by ISO 8859-8. You are writing an application to display this file in a TextArea. The local encoding is already set to 8859-8. How can you write a chunk of code to read the first line from this file?
You have three variables accessible to you:
myfile is the name of the file you want to read
stream is an InputStream object associated with this file
s is a String object
Select all valid answers.
A)
InputStreamReader reader = new InputStreamReader(stream, "8859-8");
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
B)
InputStreamReader reader = new InputStreamReader(stream);
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
C)
InputStreamReader reader = new InputStreamReader(myfile, "8859-8");
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
D)
InputStreamReader reader = new InputStreamReader(myfile);
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
E)
FileReader reader = new FileReader(myfile);
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
56. Which of the following used to read and write to network sockets, which are super classes of Low level streams?
A) InputStream
B) StreamReaders
C) OutputStream
D) Writers
E) Readers
F) Streams
57. Low Level Streams read input as bytes and writes as bytes, then select the correct declarations of Streams.
A) FileInputStream FIS = new FileInputStream("test.txt")
B) File file = new File("test.txt"); FileInputStream FIS = new FileInputStream(file)
C) File file = new File("c:\\"); File file1 = new File(file,"test.txt"); FileOutputStream FOS = new FileOutputStream(file1);
D) FileInputStream FIS = new FileInputStream("c:\\","test.txt")
58. Choose all valid forms of the argument list for the FileOutputStream constructor shown below:
A) FileOutputStream( FileDescriptor fd )
B) FileOutputStream( String n, boolean a )
C) FileOutputStream( boolean a )
D) FileOutputStream()
E) FileOutputStream( File f )
59. What is the class that has "mode" argument such as "r" or "rw" is required in the constructor:
A) DataInputStream
B) InputStream
C) RandomAccessFile
D) File
60. What is the output displayed by the following code?
import java.io.*;
public class TestIPApp {
public static void main(String args[]) {
RandomAccessFile file = new RandomAccessFile("test.txt", "rw");
file.writeBoolean(true);
file.writeInt(123456);
file.writeInt(7890);
file.writeLong(1000000);
file.writeInt(777);
file.writeFloat(.0001f);
file.seek(5);
System.out.println(file.readInt());
file.close();
}
}
Select correct answer:
A) 123456
B) 7890
C) 1000000
D) .0001
Answers # 2
1. Answer
A) String str[];
C) String str[ ]=new string [ ] {"string1", "string 2", "string3", "string4", "string5"};
D) String str[ ]= {"string1","string2", "string3", "string4", "string5"};
2. Answer
A) final
D) static
3. Answer
B) Method declarations.
C) Block of code declarations
4. Answer
A) "Class A Constructor" followed by "Class B Constructor"
5. Answer
A) super(100);
6. Answer
A) Overridden methods have the same method name and signature
D) Overloaded methods have the same method name and different signature
7. Answer
C) The values 100,100,100 printed
8. Answer
B) break middle;
9. Answer
A) Compile time error
D) MyMethod() cannot throw an exception in MyExp2 class
10. Answer
A) Compilation error
11. Answer
A) The garbage collector runs in low memory situations
C) When it runs it releases the memory allocated by an object.
12. Answer
A) 1
13. Answer
B) goto
E) import, package
NOTE: The keywords 'const' and 'goto' are reserved by Java, even though they are not currently used in Java. For more information at http://java.sun.com/docs/books/jls/html/3.doc.html#229308
14. Answer
B) new Inner() {
15. Answer
A) An anonymous class cannot have any constructors
D) An anonymous class instantiated and declared in the same place.
16. Answer
B) abstract class A { abstract void Method() ; }
17. Answer
C) Does not compile
18. Answer
B) Compiles and runs printing out "HelloHowAreYou"
19. Answer
A) goto
B) synchronized
C) extends
D) implements
E) this
20. Answer
C) Exception is thrown
21. Answer
A) long l = 698.65;
B) float f = 55.8;
22. Answer
C) -(2^31) to (2^31 - 1)
23. Answer
0X7, 0x7, 0x07, 0X07
24.Answer
0 to 2^16-1
25. Answer
A) int getID()
26. Answer
A) Compile time error
27. Answer
B) Java 1.0 and Java 1.1 event handling models are not compatible
C) Event listeners are the objects that implements listener interfaces.
D) You can add multiple listeners to any event source, then there is no guarantee that the listeners will be notified in the order in which they were added.
28. Answer
B) 0x77 >>> 1;
C) 0x77 >> 1;
29. Answer
A) char c = 'a';
B) double d = 45.6;
D) int k = 8;
30. Answer
A) b instanceof Button
31. Answer
C) A equals A modulus 5.
32. Answer
C) No output
33. Answer
D) "The value of s is HelloWorld" is printed on the screen
34. Answer
B) b1 || b2;
Explanation:
A) This returns false. == is used as comparison operator.
B) This returns true. Because of OR operation.
C) There is no operator like that.
D) This returns false. This is because of AND operation.
NOTE: The operators ||, && are called Short-Circuit operators. The operator || ( OR Operation ) returns true if one operand is true without regard to the other operand. The operator && ( AND Operation ) returns false if one operand is false, without regard to the other operand . In our example b1 is true and b2 is false.
35. Answer
A) "The x value is 20.
36. Answer
B) By making methods are public and variables as private
37. Answer
A) public void amethod(String s, int i){}
D) public void Amethod(int i, String s) {}
38. Answer
D) Base b = new Base(10);
Explanation:
A) This is wrong because there is no maching constructor defined in Derived class.
B) The super keyword suppose to be the first line in the constructor.
C) The this keyword suppose to be first line in hte constructor.
D) This is correct because there is matching constructor in Base class.
39. Answer
A) An anonymous class cannot have any constructors
D) An anonymous inner class can implement an interface
40. Answer
A) The compiler error
41. Answer
A) Threads start() method automatically calls run() method .
B) Thread dies after the run() returns
D) A stop() method kills the currently running Thread
42. Answer
A) Allow threads to be manipulated as group
C) May contain other ThreadGroups
43. Answer
A) Frame's default Layout Manager is Border
B) Applet's is Flow Layout
C) Panel's is Flow Layout
D) A Dialog is a pop up window and used as BorderLayout as default.
44. Answer
A) Weight x and weight y should be 0.0 and 1.0
B) If fill is both, anchor does not make sense.
C) While constructing GridBagLayout , you won't tell how many rows and columns the underlying grid has.
45. Answer
A) gridwidth, gridheight, specifies how many columns and rows to span.
B) gridx, gridy has GridBagConstraints.RELATIVE which adds left to right and top to bottom, still you can specify gridwidth and gridheight except for last component, which you have to set GridBagConstraints.REMAINDER.
46. Answer
C) Compiler fails at the time of Math class instantiation
47. Answer
A) 145.0 followed by -145.0
48. Answer
A) int a = 10; float f = 10; if ( a = = f) { System.out.println("Equal");}
49.Answer
A) List
50. Answer
A) true
51. Answer
B) collection
52. Answer
C) List
53. Answer
C) c:\source\Ran.test
54. Answer
A) File f = new File("/","autoexec.bat");
B) DataInputStream d = new DataInputStream(System.in);
C) OutputStreamWriter o = new OutputStreamWriter(System.out);
55. Answer
A)
InputStreamReader reader = new InputStreamReader(stream, "8859-8");
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
B)
InputStreamReader reader = new InputStreamReader(stream);
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
E)
FileReader reader = new FileReader(myfile);
BufferedReader buffer = new BufferedReader(reader);
s = buffer.readLine();
56. Answer
A) InputStream
C) OutputStream
57. Answer
A) FileInputStream FIS = new FileInputStream("test.txt")
B) File file = new File("test.txt"); FileInputStream FIS = new FileInputStream(file)
C) File file = new File("c:\\"); File file1 = new File(file,"test.txt"); FileOutputStream FOS = new FileOutputStream(file1);
58. Answer
A) FileOutputStream( FileDescriptor fd )
B) FileOutputStream( String n, boolean a )
E) FileOutputStream( File f )
59. Answer
C) RandomAccessFile
60. Answer
B) 7890
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