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JAVA TECHNICAL QUESTIONS

QUESTION 1:

        Given:
        1 public class test {
        2 public static void main (String args[]) {
        3 int i = 0xFFFFFFF1;
        4 int j = ~i;
        5
        6 }
        7 }
        What is the decimal value of j at line 5?
        A. 0
        B. 1
        C. 8
        D. -15
        E. An error at line 3 causes compilation to fail.
        F. An error at line 4 causes compilation to fail.

Answer: C

QUESTION 2:

        Given:
        Integer i = new Integer (42);
        Long 1 = new Long (42);
        Double d = new Double (42.0);
        Which two expressions evaluate to True? (Choose Two)
        A. (i ==1)
        B. (i == d)
        C. (d == 1)
        D. (i.equals (d))
        E. (d.equals (i))
        F. (i.equals (42))

Answer: D, E

QUESTION 3:

        Exhibit :
        1 public class test {
        2 private static int j = 0;
        3
        4 private static boolean methodB(int k) {
        5 j += k;
        6 return true;
        1 }
        2
        3 public static void methodA(int i) {
        4 boolean b:
        5 b = i < 10 | methodB (4);
        6 b = i < 10 || methodB (8);
        7 }
        8
        9 public static void main (String args[]) {
        10 methodA (0);
        11 system.out.printIn(j);
        12 }
        13 }
        What is the result?
        A. The program prints "0"
        B. The program prints "4"
        C. The program prints "8"
        D. The program prints "12"
        E. The code does not complete.

Answer: B

QUESTION 4:

        Given
        1 Public class test {
        2 Public static void main (String args[]) {
        3 System.out.printIn (6 ^ 3);
        4 }
        5 }
        What is the output?

Answer: 5

QUESTION 5:

        Given:
        1 public class Foo {
        2 public static void main (String [] args) {
        3 StringBuffer a = new StringBuffer ("A");
        4 StringBuffer b = new StringBuffer ("B");
        5 operate (a,b);
        6 system.out.printIn(a + "," +b);
        7 }
        8 static void operate (StringBuffer x, StringBuffer y) {
        9 x.append(y);
        10 y = x;
        11 }
        12 }
        What is the result?
        A. The code compiles and prints "A,B".
        B. The code compiles and prints "A,A".
        C. The code compiles and prints "B,B".
        D. The code compiles and prints "AB,B".
        E. The code compiles and prints "AB,AB".
        F. The code does not compile because "+" cannot be overloaded for StringBuffer.

Answer: D

QUESTION 6:

        Exhibit:
        1 Public class test {
        2 Public static void stringReplace (String text) {
        3 Text = text.replace ('j' , 'i');
        4 }
        5
        6 public static void bufferReplace (StringBuffer text) {
        7 text = text.append ("C")
        8 }
        9
        10 public static void main (String args[]) {
        11 String textString = new String ("java");
        12 StringBuffer text BufferString = new StringBuffer ("java");
        13
        14 stringReplace (textString);
        15 BufferReplace (textBuffer);
        16
        17 System.out.printLn (textString + textBuffer);
        18 }
        19 }
        What is the output?

Answer: JAVAJAVA

QUESTION 7:

        Exhibit:
        1 public class test {
        2 public static void add3 (Integer i) {
        3 int val = i.intValue ( );
        4 val += 3;
        5 i = new Integer (val);
        6 }
        7
        8 public static void main (String args [ ] ) {
        9 Integer i = new Integer (0);
        10 add3 (i);
        11 system.out.printIn (i.intValue ( ) );
        12 }
        13 }
        What is the result?
        A. Compilation will fail.
        B. The program prints "0".
        C. The program prints "3".
        D. Compilation will succeed but an exception will be thrown at line 3.

Answer: B

QUESTION 8:

        Given:
        1 public class ConstOver {
        2 public ConstOver (int x, int y, int z) {
        3 }
        4 }
        Which two overload the ConstOver constructor? (Choose Two)
        A. ConstOver ( ) { }
        B. Protected int ConstOver ( ) { }
        C. Private ConstOver (int z, int y, byte x) { }
        D. Public Object ConstOver (int x, int y, int z) { }
        E. Public void ConstOver (byte x, byte y, byte z) { }

Answer: A, C

QUESTION 9:

        Given:
        1 public class MethodOver {
        2 public void setVar (int a, int b, float c) {
        3 }
        4 }
        Which two overload the setVar method? (Choose Two)
        A. Private void setVar (int a, float c, int b) { }
        B. Protected void setVar (int a, int b, float c) { }
        C. Public int setVar (int a, float c, int b) {return a;}
        D. Public int setVar (int a, int b, float c) {return a;}
        E. Protected float setVar (int a, int b, float c) {return c;}

Answer: A, C

# QUESTION 10:

        Given:
        1 class BaseClass {
        2 Private float x = 1.0f ;
        3 protected float getVar ( ) { return x;}
        4 }
        5 class Subclass extends BaseClass {
        6 private float x = 2.0f;
        7 //insert code here
        8 }
        Which two are valid examples of method overriding? (Choose Two)
        A. Float getVar ( ) { return x;}
        B. Public float getVar ( ) { return x;}
        C. Float double getVar ( ) { return x;}
        D. Public float getVar ( ) { return x;}
        E. Public float getVar (float f ) { return f;}

Answer: B, D

QUESTION 11:

        Which two demonstrate an "is a" relationship? (Choose Two)
        A. public interface Person { }
        public class Employee extends Person { }
        B. public interface Shape { }
        public class Employee extends Shape { }
        C. public interface Color { }
        public class Employee extends Color { }
        D. public class Species { }
        public class Animal (private Species species)
        E. interface Component { }
        Class Container implements Component {
        Private Component[ ] children;
        }

Answer: D, E

QUESTION 12:

        Which statement is true?
        A. An anonymous inner class may be declared as final.
        B. An anonymous inner class can be declared as private.
        C. An anonymous inner class can implement multiple interfaces.
        D. An anonymous inner class can access final variables in any enclosing scope.
        E. Construction of an instance of a static inner class requires an instance of the enclosing outer class.

Answer: D

QUESTION 13:

        Given:
        1 package foo;
        2
        3 public class Outer {
        4 public static class Inner {
        5 }
        6 }
        Which statement is true?
        A. An instance of the Inner class can be constructed with "new Outer.Inner ()"
        B. An instance of the inner class cannot be constructed outside of package foo.
        C. An instance of the inner class can only be constructed from within the outer class.
        D. From within the package bar, an instance of the inner class can be constructed with "new inner()"

Answer: A

QUESTION 8:

        Exhibit:
        1 public class enclosingone {
        2 public class insideone{ }
        3 }
        4 public class inertest{
        5 public static void main (string[]args){
        6 enclosingone eo= new enclosingone ();
        7 //insert code here
        8 }
        9 }
        Which statement at line 7 constructs an instance of the inner class?
        A. InsideOnew ei= eo.new InsideOn();
        B. Eo.InsideOne ei = eo.new InsideOne();
        C. InsideOne ei = EnclosingOne.new InsideOne();
        D. EnclosingOne.InsideOne ei = eo.new InsideOne();

Answer: D

QUESTION 15:

        Exhibit:
        1 interface foo {
        2 int k = 0;
        3 }
        4
        5 public class test implements Foo {
        6 public static void main(String args[]) {
        7 int i;
        8 Cert cert = new test ();
        9 i= Cert.k;
        10.i= Cert.k;
        11.i= Foo.k;
        12.}
        13.}
        8.
        What is the result?
        A. Compilation succeeds.
        B. An error at line 2 causes compilation to fail.
        C. An error at line 9 causes compilation to fail.
        D. An error at line 10 causes compilation to fail.
        E. An error at line 11 causes compilation to fail.

Answer: A

QUESTION 16:

        Given:
        1 //point X
        2 public class foo {
        3 public static void main (String[]args) throws Exception {
        4 printWriter out = new PrintWriter (new
        5 java.io.outputStreamWriter (System.out), true);
        6 out.printIn("Hello");
        7 }
        8 }
        Which statement at PointX on line 1 allows this code to compile and run?
        A. Import java.io.PrintWriter;
        B. Include java.io.PrintWriter;
        C. Import java.io.OutputStreamWriter;
        D. Include java.io.OutputStreamWriter;
        E. No statement is needed.

Answer: A

QUESTION 17:

        Which two statements are reserved words in Java? (Choose Two)
        A. Run
        B. Import
        C. Default
        D. Implement

Answer: B, C

QUESTION 18:

        Which three are valid declarations of a float? (Choose Three)
        A. Float foo = -1;
        B. Float foo = 1.0;
        C. Float foo = 42e1;
        D. Float foo = 2.02f;
        E. Float foo = 3.03d;
        F. Float foo = 0x0123;

Answer: A, D, F

QUESTION 19:

        Given:
        1 int index = 1;
        2 boolean[] test = new Boolean[3];
        3 boolean foo= test [index]; What is the result?
        A. Foo has the value of 0.
        B. Foo has the value of null.
        C. Foo has the value of true.
        D. Foo has the value of false.
        E. An exception is thrown.
        F. The code will not compile.

Answer: D

QUESTION 20:

        Given:
        1 public class test{
        2 public static void main(string[]args){
        3 string foo = args [1];
        4 string foo = args [2];
        5 string foo = args [3];
        6 }
        7 }
        And command line invocation:
        Java Test red green blue
        What is the result?
        A. Baz has the value of ""
        B. Baz has the value of null
        C. Baz has the value of "red"
        D. Baz has the value of "blue"
        E. Bax has the value of "green"
        F. The code does not compile.
        G. The program throws an exception.

Answer: G

QUESTION 21:

        Given:
        1 int index = 1;
        2 int [] foo = new int [3]; 10.int bar = foo [index]; 11.int baz = bar + index; What is the result?
        A. Baz has the value of 0
        B. Baz has the value of 1
        C. Baz has the value of 2
        D. An exception is thrown.
        E. The code will not compile.

Answer: B

QUESTION 22:

        Given:
        1 public class foo {
        2 public static void main (String[]args) {
        3 String s;
        4 system.out.printIn ("s=" + s);
        5 }
        6 }
        What is the result?
        A. The code compiles and "s=" is printed.
        B. The code compiles and "s=null" is printed.
        C. The code does not compile because string s is not initialized.
        D. The code does not compile because string s cannot be referenced.
        E. The code compiles, but a NullPointerException is thrown when toString is called.

Answer: C

QUESTION 23:

        Which will declare a method that forces a subclass to implement it?
        A. Public double methoda();
        B. Static void methoda (double d1) {}
        C. Public native double methoda();
        D. Abstract public void methoda();
        E. Protected void methoda (double d1){}

Answer: D

QUESTION 24:

        You want subclasses in any package to have access to members of a superclass. Which is the most
        restrictive access modifier that will accomplish this objective?
        A. Public
        B. Private
        C. Protected
        D. Transient
        E. No access modifier is qualified

Answer: C

QUESTION 25:

        Given:
        1 abstract class abstrctIt {
        2 abstract float getFloat ();
        3 }
        4 public class AbstractTest extends AbstractIt {
        5 private float f1= 1.0f;
        6 private float getFloat () {return f1;}
        7 }
        What is the result?
        A. Compilation is successful.
        B. An error on line 6 causes a runtime failure.
        C. An error at line 6 causes compilation to fail.
        D. An error at line 2 causes compilation to fail.

Answer: C

QUESTION 26:

        Exhibit:
        1 public class test{
        2 public int aMethod(){
        3 static int i=0;
        4 i++;
        5 return I;
        6 }
        7 public static void main (String args[]){
        8 test test = new test();
        9 test.aMethod();
        10.int j = test.aMethod();
        11.System.out.printIn(j);
        12.}
        13.}
        What is the result?
        A. Compilation will fail.
        B. Compilation will succeed and the program will print "0"
        C. Compilation will succeed and the program will print "1"
        D. Compilation will succeed and the program will print "2"

Answer: D

QUESTION 27:

        Given:
        1 class super {
        2 public float getNum() {return 3.0f;}
        3 }
        4
        5 public class Sub extends Super {
        6
        7 }
        Which method, placed at line 6, will cause a compiler error?
        A. Public float getNum() {return 4.0f; }
        B. Public void getNum () { }
        C. Public void getNum (double d) { }
        D. Public double getNum (float d) {retrun 4.0f; }

Answer: B

QUESTION 28:

        Which declaration prevents creating a subclass of an outer class?
        A. Static class FooBar{ }
        B. Private class FooBar{ }
        C. Abstract public class FooBar{ }
        D. Final public class FooBar{ }
        E. Final abstract class FooBar{ }

Answer: D

QUESTION 29:

        Given:
        1 byte [] arry1, array2[];
        2 byte array3 [][];
        3 byte[][] array4;
        If each array has been initialized, which statement will cause a compiler error?
        A. Array2 = array1;
        B. Array2 = array3;
        C. Array2 = array4;
        D. Both A and B
        E. Both A and C
        F. Both B and C

Answer: F

QUESTION 30:

        Exhibit:
        1 class super {
        2 public int I = 0;
        3
        4 public super (string text) {
        5 I = 1
        6 }
        7 }
        8
        9 public class sub extends super {
        10 public sub (string text) {
        11 i= 2
        12 }
        13
        8 public static void main (straing args[]) {
        15 sub sub = new sub ("Hello");
        16 system.out. PrintIn(sub.i);
        17 }
        18 }
        What is the result?
        A. Compilation will fail.
        B. Compilation will succeed and the program will print "0"
        C. Compilation will succeed and the program will print "1"
        D. Compilation will succeed and the program will print "2"

Answer: A

QUESTION 31:

        Given:
        1 public class returnIt {
        2 returnType methodA(byte x, double y) {
        3 return (short) x/y * 2;
        4 }
        5 }
        What is the valid returnType for methodA in line 2?
        A. Int
        B. Byte
        C. Long
        D. Short
        E. Float
        F. Double

Answer: F

QUESTION 32:

        Given the ActionEvent, which method allows you to identify the affected component?
        A. GetClass.
        B. GetTarget.
        C. GetSource.
        D. GetComponent.
        E. GetTargetComponent.

Answer: C

QUESTION 33:

        Which is a method of the MouseMotionListener interface?
        A. Public void mouseMoved(MouseEvent)
        B. Public boolean mouseMoved(MouseEvent)
        C. Public void mouseMoved(MouseMotionEvent)
        D. Public boolean MouseMoved(MouseMotionEvent)
        E. Public boolean mouseMoved(MouseMotionEvent)

Answer: A

QUESTION 34:

        Exhibit:
        1 import java.awt*;
        2
        3 public class X extends Frame {
        4 public static void main(string []args) {
        5 X x = new X ();
        6 X.pack();
        7 x.setVisible(true);
        8 }
        9
        10 public X () {
        11 setlayout (new GridLayout (2,2));
        12
        13 Panel p1 = new panel();
        8 Add(p1);
        15 Button b1= new Button ("One");
        16 P1.add(b1);
        17
        18 Panel p2 = new panel();
        19 Add(p2);
        20 Button b2= new Button ("Two");
        21 P2.add(b2);
        22
        23 Button b3= new Button ("Three");
        24 add(b3);
        25
        26 Button b4= new Button ("Four");
        27 add(b4);
        28 }
        29 }
        Which two statements are true? (Choose Two)
        A. All the buttons change height if the frame height is resized.
        B. All the buttons change width if the Frame width is resized.
        C. The size of the button labeled "One" is constant even if the Frame is resized.
        D. Both width and height of the button labeled "Three" might change if the Frame is resized.

Answer: C, D

QUESTION 35:

        You are assigned the task of building a panel containing a TextArea at the top, a label directly below it,
        and a button directly below the label. If the three components are added directly to the panel. Which
        layout manager can the panel use to ensure that the TextArea absorbs all of the free vertical space when
        the panel is resized?
        A. GridLayout.
        B. CardLayout.
        C. FlowLayout.
        D. BorderLayout.
        E. GridBagLayout.

Answer: E

QUESTION 36:

        Which gets the name of the parent directory file "file.txt"?
        A. String name= File.getParentName("file.txt");
        B. String name= (new File("file.txt")).getParent();
        C. String name = (new File("file.txt")).getParentName();
        D. String name= (new File("file.txt")).getParentFile();
        E. Directory dir=(new File ("file.txt")).getParentDir();
        String name= dir.getName();

Answer: B

QUESTION 37:

        Which can be used to encode charS for output?
        A. Java.io.OutputStream.
        B. Java.io.OutputStreamWriter.
        C. Java.io.EncodeOutputStream.
        D. Java.io.EncodeWriter.
        E. Java.io.BufferedOutputStream.

Answer: B

QUESTION 38:

        The file "file.txt" exists on the file system and contsins ASCII text. Given:
        1 try {
        2 File f = new File("file.txt");
        3 OutputStream out = new FileOutputStream(f, true);
        4 }
        5 catch (IOException) { } What is the result?
        A. The code does not compile.
        B. The code runs and no change is made to the file.
        C. The code runs and sets the length of the file to 0.
        D. An exception is thrown because the file is not closed.
        E. The code runs and deletes the file from the file system.

Answer: A

QUESTION 39:

        Which constructs a DataOutputStream?
        A. New dataOutputStream("out.txt");
        B. New dataOutputStream(new file("out.txt"));
        C. New dataOutputStream(new writer("out.txt"));
        D. New dataOutputStream(new FileWriter("out.txt"));
        E. New dataOutputStream(new OutputStream("out.txt"));
        F. New dataOutputStream(new FileOutputStream("out.txt"));

Answer: F

QUESTION 40:

        What writes the text "<end>" to the end of the file "file.txt"?
        A. OutputStream out= new FileOutputStream ("file.txt"); Out.writeBytes ("<end>/n");
        B. OutputStream os= new FileOutputStream ("file.txt", true); DataOutputStream out = new
        DataOutputStream(os); out.writeBytes ("<end>/n");
        C. OutputStream os= new FileOutputStream ("file.txt"); DataOutputStream out = new
        DataOutputStream(os); out.writeBytes ("<end>/n");
        D. OutputStream os= new OutputStream ("file.txt", true); DataOutputStream out = new
        DataOutputStream(os); out.writeBytes ("<end>/n");

Answer: B

QUESTION 41:

        Given:
        1 public class X {
        2 public object m () {
        3 object o = new float (3.8F);
        4 object [] oa = new object [1];
        5 oa[0]= o;
        6 o = null;
        7 return oa[0];
        8 }
        9 }
        When is the float object created in line 3, eligible for garbage collection?
        A. Just after line 5
        B. Just after line 6
        C. Just after line 7 (that is, as the method returns)
        D. Never in this method.

Answer: D

QUESTION 42:

        Given:
        1 string foo = "ABCDE";
        2 foo.substring(3);
        3 foo.concat("XYZ");
        4 Type the value of foo at line 6.

Answer: ABCDE

QUESTION 43:

        Which method is an appropriate way to determine the cosine of 42 degrees?
        A. Double d = Math.cos(42);
        B. Double d = Math.cosine(42);
        C. Double d = Math.cos(Math.toRadians(42));
        D. Double d = Math.cos(Math.toDegrees(42));
        E. Double d = Math.cosine(Math.toRadians(42));

Answer: C

QUESTION 44:

        You need to store elements in a collection that guarantees that no duplicates are stored and all elements
        can be accessed in natural order. Which interface provides that capability?
        A. Java.util.Map.
        B. Java.util.Set.
        C. Java.util.List.
        D. Java.util.StoredSet.
        E. Java.util.StoredMap.
        F. Java.util.Collection.

Answer: D

QUESTION 45:

        Which statement is true for the class java.util.HashSet?
        A. The elements in the collection are ordered.
        B. The collection is guaranteed to be immutable.
        C. The elements in the collection are guaranteed to be unique.
        D. The elements in the collection are accessed using a unique key.
        E. The elements in the collections are guaranteed to be synchronized.

Answer: C

QUESTION 46:

        Given:
        1 public class IfTest {
        2 public static void main(string[]args) {
        3 int x = 3;
        4 int y = 1;
        5 if (x = y)
        6 system.out.printIn("Not equal");
        7 else
        8 system.out.printIn("Equal");
        9 }
        10 }
        What is the result?
        A. The output is "Equal"
        B. The output in "Not Equal"
        C. An error at line 5 causes compilation to fall.
        D. The program executes but does not print a message.

Answer: C

QUESTION 47:

        Exhibit:
        1 public class test {
        2 public static void main(string args[]) {
        3 int 1= 0;
        4 while (i) {
        5 if (i==4) {
        6 break;
        7 }
        8 ++i;
        9 }
        10
        11 }
        12 }
        What is the value of i at line 10?
        A. 0
        B. 3
        C. 4
        D. 5
        E. The code will not compile.

Answer: E

QUESTION 48:

        Given:
        1 int i= 1, j= 10 ;
        2 do {
        3 if (i++> --j) continue;
        4 } while (i<5);
        After execution, what are the values for I and j?
        A. i = 6 and j= 5
        B. i = 5 and j= 5
        C. i = 6 and j= 4
        D. i = 5 and j= 6
        E. i = 6 and j= 6

Answer: D

QUESTION 49:

        Given:
        1 switch (i) {
        2 default:
        3 System.out.printIn("Hello");
        4 }
        What are the two acceptable types for the variable i? (Choose Two)
        A. Char
        B. Byte
        C. Float
        D. Double
        E. Object

Answer: A, B

QUESTION 50:

        Given:
        1 public class foo {
        2 public static void main (string[]args)
        3 try {return;}
        4 finally {system.out.printIn("Finally");}
        5 }
        6 }
        What is the result?
        A. The program runs and prints nothing.
        B. The program runs and prints "Finally"
        C. The code compiles, but an exception is thrown at runtime.
        D. The code will not compile because the catch block is missing.

Answer: B

QUESTION 51:

        Exhibit:
        1 import java.io.IOException;
        2 public class ExceptionTest{
        3 public static void main (String[]args){
        4 try {
        5 methodA();
        6 } catch (IOException e) {
        7 system.out.printIn("Caught IOException");
        8 } catch (Exception e) {
        9 system.out.printIn("Caught Exception");
        10 }
        11 }
        12 public void methodA () {
        13 throw new IOException ();
        14 }
        15 }