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;
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 a
method declared with the keyword synchronized
4) Thread scheduling algorithms
are platform dependent
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.
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) An anonymous class may have
only one constructor
4) An inner class may extend another class
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"
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;
What will be output by the following line of code?
System.out.println(010|4);
1) 14
2) 0
3) 6
4) 12
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;
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");
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;
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.println(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.println(v.i+ " "+i);
}//End of another
}
1) 10,0, 30
2) 20,0,30
3) 20,99,30
4) 10,0,20
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) {}
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);
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);
Which of the following are methods of the Thread class?
1) yield()
2) sleep(long msec)
3) go()
4) stop()
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
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
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){}
Which of the following are methods of the Collection interface?
1)
iterator
2) isEmpty
3) toArray
4) setText
Which of the following best describes the use of the synhronized 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