class MyThread extends Thread
{
public static void main(String [] args)
{
MyThread t = new MyThread();
t.start();
System.out.print("one. ");
t.start();
System.out.print("two. ");
}
public void run()
{
System.out.print("Thread ");
}
}
A -
Compilation fails
B -
An exception occurs at runtime.
C -
It prints "Thread one. Thread two."
D -
The output cannot be determined.
2-
What will be the output of the program?
class MyThread extends Thread
{
MyThread() {}
MyThread(Runnable r) {super(r); }
public void run()
{
System.out.print("Inside Thread ");
}
}
class MyRunnable implements Runnable
{
public void run()
{
System.out.print(" Inside Runnable");
}
}
class Test
{
public static void main(String[] args)
{
new MyThread().start();
new MyThread(new MyRunnable()).start();
}
}
A -
Prints "Inside Thread Inside Thread"
B -
Prints "Inside Thread Inside Runnable"
C -
Does not compile
D -
Throws exception at runtime
3-
What will be the output of the program?
class s implements Runnable
{
int x, y;
public void run()
{
for(int i = 0; i < 1000; i++)
synchronized(this)
{
x = 12;
y = 12;
}
System.out.print(x + " " + y + " ");
}
public static void main(String args[])
{
s run = new s();
Thread t1 = new Thread(run);
Thread t2 = new Thread(run);
t1.start();
t2.start();
}
}
A -
DeadLock
B -
It print 12 12 12 12
C -
Compilation Error
D -
Cannot determine output.
4-
public class Test
{
public void foo()
{
assert false; /* Line 5 */
assert false; /* Line 6 */
}
public void bar()
{
while(true)
{
assert false; /* Line 12 */
}
assert false; /* Line 14 */
}
}
What causes compilation to fail?
A -
Line 5
B -
Line 6
C -
Line 12
D -
Line 14
5-
What will be the output of the program?
public class Test
{
public static int y;
public static void foo(int x)
{
System.out.print("foo ");
y = x;
}
public static int bar(int z)
{
System.out.print("bar ");
return y = z;
}
public static void main(String [] args )
{
int t = 0;
assert t > 0 : bar(7);
assert t > 1 : foo(8); /* Line 18 */
System.out.println("done ");
}
}
A -
bar
B -
bar done
C -
foo done
D -
Compilation fails
6-
Which of the following statements is true?
A -
In an assert statement, the expression after the colon ( : ) can be any Java expression.
B -
If a switch block has no default, adding an assert default is considered appropriate.
C -
In an assert statement, if the expression after the colon ( : ) does not have a value, the assert's error message will be empty.
D -
It is appropriate to handle assertion failures using a catch clause.
7-
public class Test2
{
public static int x;
public static int foo(int y)
{
return y * 2;
}
public static void main(String [] args)
{
int z = 5;
assert z > 0; /* Line 11 */
assert z > 2: foo(z); /* Line 12 */
if ( z < 7 )
assert z > 4; /* Line 14 */
switch (z)
{
case 4: System.out.println("4 ");
case 5: System.out.println("5 ");
default: assert z < 10;
}
if ( z < 10 )
assert z > 4: z++; /* Line 22 */
System.out.println(z);
}
}
which line is an example of an inappropriate use of assertions?
A -
Line 11
B -
Line 12
C -
Line 14
D -
Line 22
8-
What will be the output of the program?
public class NFE
{
public static void main(String [] args)
{
String s = "42";
try
{
s = s.concat(".5"); /* Line 8 */
double d = Double.parseDouble(s);
s = Double.toString(d);
int x = (int) Math.ceil(Double.valueOf(s).doubleValue());
System.out.println(x);
}
catch (NumberFormatException e)
{
System.out.println("bad number");
}
}
}
A -
42
B -
42.5
C -
43
D -
bad number
9-
What will be the output of the program?
public class Test138
{
public static void stringReplace (String text)
{
text = text.replace ('j' , 'c'); /* Line 5 */
}
public static void bufferReplace (StringBuffer text)
{
text = text.append ("c"); /* Line 9 */
}
public static void main (String args[])
{
String textString = new String ("java");
StringBuffer textBuffer = new StringBuffer ("java"); /* Line 14 */
stringReplace(textString);
bufferReplace(textBuffer);
System.out.println (textString + textBuffer);
}
}
A -
java
B -
javac
C -
javajavac
D -
Compile error
10-
What will be the output of the program (in jdk1.6 or above)?
public class BoolTest
{
public static void main(String [] args)
{
Boolean b1 = new Boolean("false");
boolean b2;
b2 = b1.booleanValue();
if (!b2)
{
b2 = true;
System.out.print("x ");
}
if (b1 & b2) /* Line 13 */
{
System.out.print("y ");
}
System.out.println("z");
}
}
