Self Test 4

1.      Given:
class Hexy {
public static void main(String[] args) {
Integer i = 42;
String s = (i<40)?”life”: (i>50)?”universe”:”everything”;
System.out.println(s);
}
}
What is the result?
A.    null
B.    life
C.    universe
D.    everything
E.    Compilation fails.
F.    An exception is thrown at runtime.

2.      Given:
1. class Example {
2.   public static void main(String[] args) {
3.     Short s = 15;
4.     Boolean b;
5.     // insert code here
6.   }
7. }
Which, inserted independently at line 5, will compile? (Choose all that apply.)
A.    b = (Number instanceof s);
B.    b = (s instanceof Short);
C.    b = s.instanceof(Short);
D.    b = (s instanceof Number);
E.    b = s.instanceof(Object);
F.    b = (s instanceof String);

3.      Given:
1. class Comp2 {
2.   public static void main(String[] args) {
3.     float f1 = 2.3f;
4.     float[][] f2 = {{42.Of}, {l.7f, 2.3f}, {2.6f, 2.7f}};
5.     float[] f3 = {2.7f};
6.     Long x = 42L;
7.     // insert code here
8.       System.out.println(“true”);
9.   }
10. }
And the following five code fragments:
F1.  if (f1 == f2)
F2.  if (f1 == f2[2][1])
F3.  if (x == f2[0][0])
F4.  if (f1 == f2 [1,1] )
F5.  if (f3 == f2 [2] )
What is true?
A.    One of them will compile, only one will be true.
B.    Two of them will compile, only one will be true.
C.    Two of them will compile, two will be true.
D.    Three of them will compile, only one will be true.
E.    Three of them will compile, exactly two will be true.
F.    Three of them will compile, exactly three will be true.

4.      Given:
class  Fork {
public static void main(String[] args)    {
if(args.length == 1 | args[1] .equals(“test”)) {
System.out.println (“test  case”);
} else {
System.out.println(“production ” + args[0]) ;
}
}
}

And the command-line invocation:
java Fork live2
What is the result?
A.    test case
B.    production
C.    test case live2
D.    Compilation fails.
E.    An exception is thrown at runtime.

5.      Given:
class Foozit {
public static void main(String[] args) {
Integer x = 0;
Integer y = 0;
for(Short z = 0; z < 5; z++)
if((++x > 2) || (++y > 2))
X++ ;
System.out.println (x + ” ” + y);
}
}
What is the result?
A.    5 1
B.    5 2
C.    5 3
D.    8 1
E.    8 2
F.    8 3
G.    10 2
H.    10 3

6.      Given:
class Titanic {
public static void main(String[] args) {
Boolean bl = true;
boolean b2 = false;
boolean b3 = true;
if((bl & b2) | (b2 & b3) & b3)
System.out.print(“alpha “);
if((bl = false) | (b1 & b3) | (bl | b2))
System.out.print(“beta “};
}
}
What is the result?
A.    beta
B.    alpha
C.    alpha beta
D.    Compilation fails.
E.    No output is produced.
F.    An exception is thrown at runtime.

7.      Given:
class Feline {
public static void main(String[] args) {
Long x = 42L;
Long y = 44L;
System.out.print (” ” + 7 + 2 + ” “) ;
System.out.print(foo () + x + 5 + ” “);
System.out.println(x + y + foo());
}
static String foo() { return “foo”; }
}
What is the result?
A.    9 foo47 86foo
B.    9 foo47 4244foo
C.    9 foo425 86foo
D.    9 foo425 4244foo
E.    72 foo47 86foo
F.    72 foo47 4244foo
G.    72 foo425 86foo
H.    72 foo425 4244foo
I.    Compilation fails.

8.      Place the fragments into the code to produce the output 33. Note, you must use each fragment exactly once.
CODE:
class Incr {
public static void main(String[] args) {
Integer x = 7;
int y = 2 ;

X    ___  ___;
___  ___  ___;
___  ___  ___;
___  ___  ___;

System.out.println(x);
}
}
FRAGMENTS:
Y     Y     Y     Y
y     x     x
-=     *=     *=     *=

9.      Given:
1. class Maybe {
2.   public static void main(String[] args) {
3.     boolean bl = true;
4.     boolean b2 = false;
5.     System.out.print(!false ^ false);
6.     System.out.print(” ” + (!b1 & (b2 = true)));
7.     System.out.println(” ” + (b2 ^ b1));
8.   }
9. }
Which are true?
A.    Line 5 produces true.
B.    Line 5 produces false.
C.    Line 6 produces true.
D.    Line 6 produces false.
E.    Line 7 produces true.
F.    Line 7 produces false.

10.      Given:
class Sixties {
public static void main(String[] args) {
int x = 5;  int y = 7 ;
System.out.print(((y * 2) % x));
System.out.print(” ” + (y % x));
}
}
What is the result?
A.    1 1
B.    1 2
C.    2 1
D.    2 2
E.    4 1
F.    4 2
G.    Compilation fails.
H.    An exception is thrown at runtime.