Q. 1 ]What will happen when you attempt to compile and run this code?
abstract class Base{
abstract public void myfunc();
public void another(){
System.out.println("Another method");
}
}
public class Abs extends Base{
public static void main(String argv[]){
Abs a = new Abs();
a.amethod();
}
public void myfunc(){
System.out.println("My Func");
}
public void amethod(){
myfunc();
}
}
1) The code will compile and run, printing out the words "My Func"
2) The compiler will complain that the Base class has non abstract methods
3) The code will compile but complain at run time that the Base class has non abstract methods
4) The compiler will complain that the method myfunc in the base class has no body, nobody at all to looove it
Q. 2 ]What will happen when you attempt to compile and run this code?
public class MyMain{
public static void main(String argv){
System.out.println("Hello cruel world");
}
}
1) The compiler will complain that main is a reserved word and cannot be used for a class
2) The code will compile and when run will print out "Hello cruel world"
3) The code will compile but will complain at run time that no constructor is defined
4) The code will compile but will complain at run time that main is not correctly defined
Q. 3 ]Which of the following are Java modifiers?
1) public
2) private
3) friendly
4) transient
5) vagrant
Q. 4 ]What will happen when you attempt to compile and run this code?
class Base{
abstract public void myfunc();
public void another(){
System.out.println("Another method");
}
}
public class Abs extends Base{
public static void main(String argv[]){
Abs a = new Abs();
a.amethod();
}
public void myfunc(){
System.out.println("My func");
}
public void amethod(){myfunc();}
}
1) The code will compile and run, printing out the words "My Func"
2) The compiler will complain that the Base class is not declared as abstract.
3) The code will compile but complain at run time that the Base class has non abstract methods
4) The compiler will complain that the method myfunc in the base class has no body, nobody at all to looove it
Q. 5 ]Why might you define a method as native?
1) To get to access hardware that Java does not know about
2) To define a new data type such as an unsigned integer
3) To write optimised code for performance in a language such as C/C++
4) To overcome the limitation of the private scope of a method
Q. 6 ]What will happen when you attempt to compile and run this code?
class Base{
public final void amethod(){
System.out.println("amethod");
}
}
public class Fin extends Base{
public static void main(String argv[]){
Base b = new Base();
b.amethod();
}
}
1) Compile time error indicating that a class with any final methods must be declared final itself
2) Compile time error indicating that you cannot inherit from a class with final methods
3) Run time error indicating that Base is not defined as final
4) Success in compilation and output of "amethod" at run time.
Q. 7 ]What will happen when you attempt to compile and run this code?
public class Mod{
public static void main(String argv[]){ }
public static native void amethod();
}
1) Error at compilation: native method cannot be static
2) Error at compilation native method must return value
3) Compilation but error at run time unless you have made code containing native amethod available
4) Compilation and execution without error
Q. 8 ]What will happen when you attempt to compile and run this code?
private class Base{ }
public class Vis{
transient int iVal;
public static void main(String elephant[]){ }
}
1) Compile time error: Base cannot be private
2) Compile time error indicating that an integer cannot be transient
3) Compile time error transient not a data type
4) Compile time error malformed main method
Q. 9 ]What happens when you attempt to compile and run these two files in the same directory?
//File P1.java
package MyPackage;
class P1{
void afancymethod(){
System.out.println("What a fancy method");
}
}
//File P2.java
public class P2 extends P1{
public static void main(String argv[]){
P2 p2 = new P2();
p2.afancymethod();
}
}
1) Both compile and P2 outputs "What a fancy method" when run
2) Neither will compile
3) Both compile but P2 has an error at run time
4) P1 compiles cleanly but P2 has an error at compile time
Q. 10]You want to find out the value of the last element of an array. You write the following code. What will happen when you compile and run it.?
public class MyAr{
public static void main(String argv[]){
int[] i = new int[5];
System.out.println(i[5]);
}
}
1) An error at compile time
2) An error at run time
3) The value 0 will be output
4) The string "null" will be output
Q. 11]You want to loop through an array and stop when you come to the last element.
Being a good java programmer and forgetting everything you ever knew about C/C++ you know that arrays contain information about their size.
Which of the following can you use?
1) myarray.length();
2) myarray.length;
3) myarray.size
4) myarray.size();
Q. 12]What best describes the appearance of an application with the following code?
import java.awt.*;
public class FlowAp extends Frame{
public static void main(String argv[]){
FlowAp fa=new FlowAp();
fa.setSize(400,300);
fa.setVisible(true);
}
FlowAp(){
add(new Button("One"));
add(new Button("Two"));
add(new Button("Three"));
add(new Button("Four"));
}
//End of constructor
}
//End of Application
1) A Frame with buttons marked One to Four placed on each edge.
2) A Frame with buutons marked One to four running from the top to bottom
3) A Frame with one large button marked Four in the Centre
4) An Error at run time indicating you have not set a LayoutManager
Q. 13]How do you indicate where a component will be positioned using Flowlayout?
1) North, South,East,West
2) Assign a row/column grid reference
3) Pass a X/Y percentage parameter to the add method
4) Do nothing, the FlowLayout will position the component
Q. 14]How do you change the current layout manager for a container
1) Use the setLayout method
2) Once created you cannot change the current layout manager of a component
3) Use the setLayoutManager method
4) Use the updateLayout method
Q. 15]Which of the following are fields of the GridBagConstraints class?
1) ipadx
2) fill
3) insets
4) width
Q. 16]What most closely matches the appearance when this code runs?
import java.awt.*;
public class CompLay extends Frame{
public static void main(String argv[]){
CompLay cl = new CompLay();
}
CompLay(){
Panel p = new Panel();
p.setBackground(Color.pink);
p.add(new Button("One"));
p.add(new Button("Two"));
p.add(new Button("Three"));
add("South",p);
setLayout(new FlowLayout());
setSize(300,300);
setVisible(true);
}
}
1) The buttons will run from left to right along the bottom of the Frame
2) The buttons will run from left to right along the top of the frame
3) The buttons will not be displayed
4) Only button three will show occupying all of the frame
Q. 17]Which statements are correct about the anchor field?
1) It is a field of the GridBagLayout manager for controlling component placement
2) It is a field of the GridBagConstraints class for controlling component placement
3) A valid setting for the anchor field is GridBagConstraints.NORTH
4) The anchor field controls the height of components added to a container
Q. 18]What will happen when you attempt to compile and run the following code?
public class Bground extends Thread{
public static void main(String argv[]){
Bground b = new Bground();
b.run();
}
public void start(){
for (int i = 0; i <10; i++){
System.out.println("Value of i = " + i);
}
}
}
1) A compile time error indicating that no run method is defined for the Thread class
2) A run time error indicating that no run method is defined for the Thread class
3) Clean compile and at run time the values 0 to 9 are printed out
4) Clean compile but no output at runtime
Q. 19]Is the following statement true or false?
When using the GridBagLayout manager, each new component requires a new instance of the GridBagConstraints class.
1) true
2) false
Q. 20]Which most closely matches a description of a Java Map?
1) A vector of arrays for a 2D geographic representation
2) A class for containing unique array elements
3) A class for containing unique vector elements
4) An interface that ensures that implementing classes cannot contain duplicate keys
Q. 21]How does the set collection deal with duplicate elements?
1) An exception is thrown if you attempt to add an element with a duplicate value
2) The add method returns false if you attempt to add an element with a duplicate value
3) A set may contain elements that return duplicate values from a call to the equals method
4) Duplicate values will cause an error at compile time
Q. 22]What can cause a thread to stop executing?
1) The program exits via a call to System.exit(0);
2) Another thread is given a higher priority
3) A call to the thread's stop method.
4) A call to the halt method of the Thread class?
Q. 23]For a class defined inside a method, what rule governs access to the variables of the enclosing method?
1) The class can access any variable
2) The class can only access static variables
3) The class can only access transient variables
4) The class can only access final variables
Q. 24]Under what circumstances might you use the yield method of the Thread class
1) To call from the currently running thread to allow another thread of the same or higher priority to run
2) To call on a waiting thread to allow it to run
3) To allow a thread of higher priority to run
4) To call from the currently running thread with a parameter designating which thread should be allowed to run
Q. 25]What will happen when you attempt to compile and run the following code
public class Hope{
public static void main(String argv[]){
Hope h = new Hope();
}
protected Hope(){
for(int i =0; i <10; i ++){
System.out.println(i);
}
}
}
1) Compilation error: Constructors cannot be declared protected
2) Run time error: Constructors cannot be declared protected
3) Compilation and running with output 0 to 10
4) Compilation and running with output 0 to 9
Q. 26]What will happen when you attempt to compile and run the following code
public class MySwitch{
public static void main(String argv[]){
MySwitch ms= new MySwitch();
ms.amethod();
}
public void amethod(){
int k=10;
switch(k){
default:
//Put the default at the bottom, not here
System.out.println("This is the default output");
break;
case 10:
System.out.println("ten");
case 20:
System.out.println("twenty");
break;
}
}}
1) None of these options
2) Compile time error target of switch must be an integral type
3) Compile and run with output "This is the default output"
4) Compile and run with output of the single line "ten"
Q. 27]Which of the following is the correct syntax for suggesting that the JVM performs garbage collection
1) System.free();
2) System.setGarbageCollection();
3) System.out.gc();
4) System.gc();
Q. 28]What will happen when you attempt to compile and run the following code
public class As{
int i = 10;
int j;
char z= 1;
boolean b;
public static void main(String argv[]){
As a = new As();
a.amethod();
}
public void amethod(){
System.out.println(j);
System.out.println(b);
}
}
1) Compilation succeeds and at run time an output of 0 and false
2) Compilation succeeds and at run time an output of 0 and true
3) Compile time error b is not initialised
4) Compile time error z must be assigned a char value
Q. 29]What will happen when you attempt to compile and run the following code with the command line "hello there"
public class Arg{
String[] MyArg;
public static void main(String argv[]){
MyArg=argv;
}
public void amethod(){
System.out.println(argv[1]);
}
}
1) Compile time error
2) Compilation and output of "hello"
3) Compilation and output of "there"
4) None of the above
Q. 30
What will happen when you attempt to compile and run the following code
public class StrEq{
public static void main(String argv[]){
StrEq s = new StrEq();
}
private StrEq(){
String s = "Marcus";
String s2 = new String("Marcus");
if(s == s2){
System.out.println("we have a match");
}else{
System.out.println("Not equal");
}
}
}
1) Compile time error caused by private constructor
2) Output of "we have a match"
3) Output of "Not equal"
4) Compile time error by attempting to compare strings using ==
Q. 31]What will happen when you attempt to compile and run the following code
import java.io.*;class Base{
public void amethod()throws FileNotFoundException{ }
}
public class ExcepDemo extends Base{
public static void main(String argv[]){
ExcepDemo e = new ExcepDemo();
}
public void amethod(){}
protected ExcepDemo(){
try{
DataInputStream din = new DataInputStream(System.in);
System.out.println("Pausing");
din.readByte();
System.out.println("Continuing");
this.amethod();
} catch(IOException ioe) {}
}
}
1) Compile time error caused by protected constructor
2) Compile time error caused by amethod not declaring Exception
3) Runtime error caused by amethod not declaring Exception
4) Compile and run with output of "Pausing" and "Continuing" after a key is hit
Q. 32]What will happen when you attempt to compile and run this program
public class Outer{
public String name = "Outer";
public static void main(String argv[]){
Inner i = new Inner();
i.showName();
}//End of main
private class Inner{
String name =new String("Inner");
void showName(){
System.out.println(name);
}
}//End of Inner class}
1) Compile and run with output of "Outer"
2) Compile and run with output of "Inner"
3) Compile time error because Inner is declared as private
4) Compile time error because of the line creating the instance of Inner
Q. 33]What will happen when you attempt to compile and run this code
//Demonstration of event handling
import java.awt.*;
import java.awt.event.*;
public class MyWc extends Frame
implements WindowListener{
public static void main(String argv[]){
MyWc mwc = new MyWc();
}
public void windowClosing(WindowEvent we){
System.exit(0);
}//End of windowClosing
public void MyWc(){
setSize(300,300);
setVisible(true);
}
}//End of class
1) Error at compile time
2) Visible Frame created that that can be closed
3) Compilation but no output at run time
4) Error at compile time because of comment before import statements
Q. 34]Which option most fully describes will happen when you attempt to compile and run the following code
public class MyAr{
public static void main(String argv[]) {
MyAr m = new MyAr();
m.amethod();
}
public void amethod(){
static int i;
System.out.println(i);
}
}
1) Compilation and output of the value 0
2) Compile time error because i has not been initialized
3) Compilation and output of null
4) Compile time error
Q. 35]Which of the following will compile correctly
1) short myshort = 99S;
2) String name = 'Excellent tutorial Mr Green';
3) char c = 17c;
4) int z = 015;
Q. 36]Which of the following are Java key words
1) double
2) Switch
3) then
4) instanceof
Q. 37]What will be output by the following line?
System.out.println(Math.floor(-2.1));
1) -2
2) 2.0
3) -3
4) -3.0
Q. 38]Given the following main method in a class called Cycle and a command line of
java Cycle one two
what will be output?
public static void main(String bicycle[]){
System.out.println(bicycle[0]);
}
1) None of these options
2) cycle
3) one
4) two
Q. 39]Which of the following statements are true?
1) At the root of the collection hierarchy is a class called Collection
2) The collection interface contains a method called enumerator
3) The interator method returns an instance of the Vector class
4) The Set interface is designed for unique elements
Q. 40]Which of the following statements are correct?
1) If multiple listeners are added to a component only events for the last listener added will be processed
2) If multiple listeners are added to a component the events will be processed for all but with no guarantee in the order
3) Adding multiple listeners to a comnponent will cause a compile time error
4) You may remove as well add listeners to a component.
Q. 41]Given the following code
class Base{ }
public class MyCast extends Base{
static boolean b1=false;
static int i = -1;
static double d = 10.1;
public static void main(String argv[]){
MyCast m = new MyCast();
Base b = new Base();
//Here
}
}
Which of the following, if inserted at the comment //Here will allow the code to compile and run without error
1) b=m;
2) m=b;
3) d =i;
4) b1 =i;
Q. 42]Which of the following statements about threading are true
1) You can only obtain a mutually exclusive lock on methods in a class that extends Thread or implements runnable
2) You can obtain a mutually exclusive lock on any object
3) A thread can obtain a mutually exclusive lock on an object by calling a synchronized method on that object.
4) Thread scheduling algorithms are platform dependent
Q. 43]Your chief Software designer has shown you a sketch of the new Computer parts system she is about to create.
At the top of the hierarchy is a Class called Computer and under this are two child classes.
One is called LinuxPC and one is called WindowsPC.
The main difference between the two is that one runs the Linux operating System and the other runs the Windows System
(of course another difference is that one needs constant re-booting and the other runs reliably).
Under the WindowsPC are two Sub classes one called Server and one Called Workstation.
How might you appraise your designers work?
1) Give the goahead for further design using the current scheme
2) Ask for a re-design of the hierarchy with changing the Operating System to a field rather than Class type
3) Ask for the option of WindowsPC to be removed as it will soon be obsolete
4) Change the hierarchy to remove the need for the superfluous Computer Class.
Q. 44]Which of the following statements are true
1) An inner class may be defined as static
2) There are NO circumstances where an inner class may be defined as private
3) A programmer may only provide one constructor for an anonymous class
4) An inner class may extend another class
Q. 45]What will happen when you attempt to compile and run the following code
int Output=10;
boolean b1 = false;
if((b1==true) && ((Output+=10)==20)){
System.out.println("We are equal "+Output);
}else{
System.out.println("Not equal! "+Output);
}
1) Compile error, attempting to peform binary comparison on logical data type
2) Compilation and output of "We are equal 10"
3) Compilation and output of "Not equal! 20"
4) Compilation and output of "Not equal! 10"
Q. 46]Given the following variables which of the following lines will compile without error?
String s = "Hello";long l = 99;double d = 1.11;int i = 1;int j = 0;
1) j= i <<s;
2) j= i<<j;
3) j=i<<d;
4) j=i<<l;
Q. 47]What will be output by the following line of code?
System.out.println(010|4);
1) 14
2) 0
3) 6
4) 12
Q. 48]Given the following variables
char c = 'c';int i = 10;double d = 10;long l = 1;String s = "Hello";
Which of the following will compile without error?
1) c=c+i;
2) s+=i;
3) i+=s;
4) c+=s;
Q. 49]Which of the following will compile without error?
1) File f = new File("/","autoexec.bat");
2) DataInputStream d = new DataInputStream(System.in);
3) OutputStreamWriter o = new OutputStreamWriter(System.out);
4) RandomAccessFile r = new RandomAccessFile("OutFile");
Q. 50]Given the folowing classes which of the following will compile without error?
interface IFace{}
class CFace implements IFace{}
class Base{}
public class ObRef extends Base{
public static void main(String argv[]){
ObRef ob = new ObRef();
Base b = new Base();
Object o1 = new Object();
IFace o2 = new CFace();
}
}
1) o1=o2;
2) b=ob;
3) ob=b;
4) o1=b;
Q. 51]Given the following code what will be the output?
class ValHold{
public int i = 10;
}
public class ObParm{
public static void main(String argv[]){
ObParm o = new ObParm();
o.amethod();
}
public void amethod(){
int i = 99;
ValHold v = new ValHold();
v.i=30;
another(v,i);
System.out.print( v.i );
}//End of amethod
public void another(ValHold v, int i){
i=0;
v.i = 20;
ValHold vh = new ValHold();
v = vh;
System.out.print(v.i);
System.out.print(i);
}//End of another
}
1) 10030
2) 20030
3) 209930
4) 10020
Q. 52]Given the following class definition, which of the following methods could be legally placed after the comment //Here
public class Rid{
public void amethod(int i, String s){}
//Here
}
1) public void amethod(String s, int i){}
2) public int amethod(int i, String s){}
3) public void amethod(int i, String mystring){}
4) public void Amethod(int i, String s) {}
Q. 53]Given the following class definition which of the following can be legally placed after the comment line //Here ?
class Base{
public Base(int i){}
}
public class MyOver extends Base{
public static void main(String arg[]){
MyOver m = new MyOver(10);
}
MyOver(int i){
super(i);
}
MyOver(String s, int i){
this(i);
//Here
}
}
1) MyOver m = new MyOver();
2) super();
3) this("Hello",10);
4) Base b = new Base(10);
Q. 54]Given the following class definition, which of the following statements would be legal after the comment //Here
class InOut{
String s= new String("Between");
public void amethod(final int iArgs){
int iam;
class Bicycle{
public void sayHello(){
//Here
}
}//End of bicycle class
}//End of amethod
public void another(){
int iOther;
}
}
1) System.out.println(s);
2) System.out.println(iOther);
3) System.out.println(iam);
4) System.out.println(iArgs);
Q. 55]Which of the following are methods of the Thread class?
1) yield()
2) sleep(long msec)
3) go()
4) stop()
Q. 56]Which of the following methods are members of the Vector class and allow you to input a new element
1) addElement
2) insert
3) append
4) addItem
Q. 57]Which of the following statements are true?
1) Adding more classes via import statements will cause a performance overhead, only import classes you actually use.
2) Under no circumstances can a class be defined with the private modifier
3) A inner class may under some circumstances be defined with the protected modifier
4) An interface cannot be instantiated
Q. 58]Which of the following are correct event handling methods
1) mousePressed(MouseEvent e){}
2) MousePressed(MouseClick e){}
3) functionKey(KeyPress k){}
4) componentAdded(ContainerEvent e){}
Q. 59]Which of the following are methods of the Collection interface?
1) iterator
2) isEmpty
3) toArray
4) setText
Q. 60]Which of the following best describes the use of the synchronized keyword?
1) Allows two process to run in paralell but to communicate with each other
2) Ensures only one thread at a time may access a method or object
3) Ensures that two or more processes will start and end at the same time
4) Ensures that two or more Threads will start and end at the same time