SCJP Questions 31-40

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Question 31
Which two code fragments correctly create and initialize a static array
of int elements? (Choose two.)
A. static final int[] a = { 100,200 };
B. static final int[] a;
static { a=new int[2]; a[0]=100; a[1]=200; }
C. static final int[] a = new int[2] { 100,200 };
D. static final int[] a;
static void init() { a = new int[3]; a[0]=100; a[1]=200; }
Answer: AB

Question 32
Given:
11. public class Ball {
12. public enum Color { RED, GREEN, BLUE };
13. public void foo() {
14. // insert code here
15. { System.out.println(c); }
16. }
17. }
Which code inserted at line 14 causes the foo method to print RED,
GREEN, and BLUE?
A. for( Color c : Color.values())
B. for( Color c = RED; c <= BLUE; c++)
C. for( Color c; c.hasNext() ; c.next())
D. for( Color c = Color[0]; c <= Color[2]; c++)
E. for( Color c = Color.RED; c <= Color.BLUE; c++)
Answer: A

Question 33
Given:
10. public class Fabric
11. public enum Color {
12. RED(0xff0000), GREEN(0x00ff00), BLUE(0x0000ff);
13. private final int rgb;
14. Color( int rgb) { this.rgb = rgb; }
15. public int getRGB() { return rgb; }
16. };
17. public static void main( String[] argv) {
18. // insert code here
19. }
20. }
Which two code fragments, inserted independently at line 18, allow the
Fabric class to compile? (Choose two.)
A. Color skyColor = BLUE;
B. Color treeColor = Color.GREEN;
C. Color purple = new Color( 0xff00ff);
D. if( RED.getRGB() < BLUE.getRGB() ) {}
E. Color purple = Color.BLUE + Color.RED;
F. if( Color.RED.ordinal() < Color.BLUE.ordinal() ) {}
Answer: BF

Question 34
Given:
11. public enum Title {
12. MR(”Mr.”), MRS(”Mrs.”), MS(”Ms.”);
13. private final String title;
14. private Title(String t) { title = t; }
15. public String format(String last, String first) {
16. return title + “ “ + first + “ “ + last;
17. }
18. }
19. public static void main(String[] args) {
20. System.out.println(Title.MR.format(”Doe”, “John”));
21. }
What is the result?
A. Mr. John Doe
B. An exception is thrown at runtime.
C. Compilation fails because of an error in line 12.
D. Compilation fails because of an error in line 15.
E. Compilation fails because of an error in line 20.
Answer: A

Question 35
Given:
11. public static void main(String[] args) {
12. Object obj =new int[] { 1,2,3 };
13. int[] someArray = (int[])obj;
14. for (int i: someArray) System.out.print(i +“ “)
15. }
‘What is the result?
A. 1 2 3
B. Compilation fails because of an error in line 12.
C. Compilation fails because of an error in line 13.
D. Compilation fails because of an error in line 14.
E. A ClassCastException is thrown at runtime.
Answer: A

Question 36
Given:
10. class Foo {
11. static void alpha() { /* more code here */ }
12. void beta() { /* more code here */ }
13. }
Which two are true? (Choose two.)
A. Foo.beta() is a valid invocation of beta().
B. Foo.alpha() is a valid invocation of alpha().
C. Method beta() can directly call method alpha().
D. Method alpha() can directly call method beta().
Answer: BC

Question 37
A programmer needs to create a logging method that can accept an
arbitrary number of arguments. For example, it may be called in these
ways:
logIt(”log message 1 “);
logIt(”log message2”,”log message3”);
logIt(”log message4”, “log message5”, “log message6);
Which declaration satisfies this requirement?
A. public void logIt(String * msgs)
B. public void logIt(String [] msgs)
C. public void logIt(String... msgs)
D. public void logIt(String msg1, String msg2, String msg3)
Answer: C

Question 38
A programmer is designing a class to encapsulate the information
about an inventory item. A JavaBeans component is needed to
do this. The Inventoryltem class has private instance variables to store
the item information:
10. private int itemId;
11. private String name;
12. private String description;
Which method signature follows the JavaBeans naming standards for
modifying the itemld instance variable?
A. itemID(int itemId)
B. update(int itemId)
C. setItemId(int itemId)
D. mutateItemId(int itemId)
E. updateItemID(int itemId)
Answer: C

Question 39
Click the Exhibit button.
1. public class A {
2.
3. private int counter = 0;
4.
5. public static int getInstanceCount() {
6. return counter;
7. }
8.
9. public A() {
10. counter++;
11. }
12.
13. }
Given this code from Class B:
25.A a1 =new A();
26. A a2 =new A();
27. A a3 =new A();
28. System.out.printIn(A.getInstanceCount() );
What is the result?
A. Compilation of class A fails.
B. Line 28 prints the value 3 to System.out.
C. Line 28 prints the value 1 to System.out.
D. A runtime error occurs when line 25 executes.
E. Compilation fails because of an error on line 28.
Answer: A

Question 40
A JavaBeans component has the following field:
11. private boolean enabled;
Which two pairs of method declarations follow the JavaBeans standard
for accessing this field? (Choose two.)
A. public void setEnabled( boolean enabled)
public boolean getEnabled()
B. public void setEnabled( boolean enabled)
public void isEnabled()
C. public void setEnabled( boolean enabled)
public boolean isEnabled()
D. public boolean setEnabled( boolean enabled)
public boolean getEnabled()
Answer: AC

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