Question: 01
Given:
11. public class Test {
12. public static void main(String [] args) {
13. int x = 5;
14. boolean b1 = true;
15. boolean b2 = false;
16.
17. if ((x == 4) && !b2 )
18. System.out.print("1 ");
19. System.out.print("2 ");
20. if ((b2 = true) && b1 )
21. System.out.print("3 ");
22. }
23. }
What is the result?
A. 2
B. 3
C. 1 2
D. 2 3
E. 1 2 3
F. Compilation fails.
G. An exception is thrown at runtime.
Answer: D
Q: 02 Given the command line java Pass2 and:
15. public class Pass2 {
16. public void main(String [] args) {
17. int x = 6;
18. Pass2 p = new Pass2();
19. p.doStuff(x);
20. System.out.print(" main x = " + x);
21. }
22.
23. void doStuff(int x) {
24. System.out.print(" doStuff x = " + x++);
25. }
26. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. doStuff x = 6 main x = 6
D. doStuff x = 6 main x = 7
E. doStuff x = 7 main x = 6
F. doStuff x = 7 main x = 7
Answer: B
Q: 03 Given:
13. public class Pass {
14. public static void main(String [] args) {
15. int x = 5;
16. Pass p = new Pass();
17. p.doStuff(x);
18. System.out.print(" main x = " + x);
19. }
20.
21. void doStuff(int x) {
22. System.out.print(" doStuff x = " + x++);
23. }
24. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. doStuff x = 6 main x = 6
D. doStuff x = 5 main x = 5
E. doStuff x = 5 main x = 6
F. doStuff x = 6 main x = 5
Answer: D
Question: 04
Given:
42. public class ClassA {
43. public int getValue() {
44.int value=0;
45. boolean setting = true;
46. String title=”Hello”;
47. if (value || (setting && title == “Hello”)) { return 1; }
48. if (value == 1 & title.equals(”Hello”)) { return 2; }
49. }
50. }
And:
70. ClassA a = new ClassA();
71. a.getValue();
What is the result?
A. 1
B. 2
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: C
5. 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.
Answer:
-> D is correct. This is a ternary nested in a ternary with a little unboxing thrown in.
Both of the ternary expressions are false.
-> A, B, C, E, and F are incorrect based on the above.
6. 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);
Answer:
-> B and D correctly use boxing and instanceof together.
-> A is incorrect because the operands are reversed. C and E use incorrect instance of syntax. F is wrong because Short isn't in the same inheritance tree as String.