Question 151
Click the Exhibit button.
1. public class SimpleCalc {
2. public int value;
3. public void calculate() { value += 7; }
4. }
And:
1. public class MultiCalc extends SimpleCalc {
2. public void calculate() { value -= 3; }
3. public void calculate(int multiplier) {
4. calculate();
5. super.calculate();
6. value *=multiplier;
7. }
8. public static void main(String[] args) {
9. MultiCalc calculator = new MultiCalc();
10. calculator.calculate(2);
11. System.out.println(”Value is: “+ calculator.value);
12. }
13. }
What is the result?
A. Value is: 8
B. Compilation fails.
C. Value is: 12
D. Value is: -12
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: A
Question 152
Given:
10. public class Hello {
11. String title;
12. int value;
13. public Hello() {
14. title += “ World”;
15. }
16. public Hello(int value) {
17. this.value = value;
18. title = “Hello”;
19. Hello();
20. }
21. }
and:
30. Hello c = new Hello(5);
31. System.out.println(c.title);
What is the result?
A. Hello
B. Hello World
C. Compilation fails.
D. Hello World 5
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: C
Question 153
Click the Exhibit button.
1. public class Car {
2. private int wheelCount;
3. private String vin;
4. public Car(String vin) {
5. this.vin = vin;
6. this.wheelCount = 4;
7. }
8. public String drive() {
9. return “zoom-zoom”;
10. }
11. public String getInfo() {
12. return “VIN: “+ vin + “wheels: “+ wheelCount;
13. }
14. }
And:
1. public class MeGo extends Car {
2. public MeGo(String vin) {
3. this.wheelCount = 3;
4. }
5. }
What two must the programmer do to correct the compilation errors?
(Choose two.)
A. insert a call to this() in the Car constructor
B. insert a call to this() in the MeGo constructor
C. insert a call to super() in the MeGo constructor
D. insert a call to super(vin) in the MeGo constructor
E. change the wheelCount variable in Car to protected
F. change line 3 in the MeGo class to super.wheelCount = 3;
Answer: DE
Question 154
Click the Exhibit button.
1. public class Employee {
2. String name;
3. double baseSalary;
4. Employee(String name, double baseSalary) {
5. this.name = name;
6. this.baseSalary = baseSalary;
7. }
8. }
And:
1. public class Salesperson extends Employee {
2. double commission;
3. public Salesperson(String name, double baseSalary,
4. double commission) {
5. // insert code here
6. }
7. }
Which code, inserted at line 7, completes the Salesperson constructor?
A. this.commission = commission;
B. superb();
commission = commission;
C. this.commission = commission;
superb();
D. super(name, baseSalary);
this.commission = commission;
E. super();
this.commission = commission;
F. this.commission = commission;
super(name, baseSalary);
Answer: D
Question 155
Given:
1. public class Blip {
2. protected int blipvert(int x) { return 0; }
3. }
4. class Vert extends Blip {
5. // insert code here
6. }
Which five methods, inserted independently at line 5, will compile?
(Choose five.)
A. public int blipvert(int x) { return 0; }
B. private int blipvert(int x) { return 0; }
C. private int blipvert(long x) { return 0; }
D. protected long blipvert(int x) { return 0; }
E. protected int blipvert(long x) { return 0; }
F. protected long blipvert(long x) { return 0; }
G. protected long blipvert(int x, int y) { return 0; }
Answer: ACEFG
Question156
Given:
10. public class Foo {
11. public int a;
12. public Foo() { a = 3; }
13. public void addFive() { a += 5; }
14. }
and:
20. public class Bar extends Foo {
21. public int a;
22. public Bar() { a = 8; }
23. public void addFive() { this.a +=5; }
24. }
invoked with:
30. Foo foo = new Bar();
31. foo.addFive();
32. System.out.println(”Value: “+ foo.a);
What is the result?
A. Value: 3
B. Value: 8
C. Value: 13
D. Compilation fails.
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: A
Question 157
Given:
10. public class SuperCaic {
11. protected static int multiply(int a, int b) { return a * b; }
12. }
and:
20. public class SubCalc extends SuperCalc {
21. public static int multiply(int a, int b) {
22. int c = super.multiply(a, b);
23. return c;
24. }
25. }
and:
30. SubCalc sc = new SubCalc();
31. System.out.println(sc.multiply(3,4));
32. System.out.println(SubCalc.multiply(2,2));
What is the result?
A. 12
4
B. The code runs with no output.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 21.
E. Compilation fails because of an error in line 22.
F. Compilation fails because of an error in line 31.
Answer: E
Question 158
Given:
1. public class Team extends java.util.LinkedList {
2. public void addPlayer(Player p) {
3. add(p);
4. }
5. public void compete(Team opponent) { /* more code here */ }
6. }
7. class Player { /* more code here */ }
Which two are true? (Choose two.)
A. This code will compile.
B. This code demonstrates proper design of an is-a relationship.
C. This code demonstrates proper design of a has-a relationship.
D. A Java programmer using the Team class could remove Player objects from a Team object.
Answer: AD
Question 159
Which four are true? (Choose four.)
A. Has-a relationships should never be encapsulated.
B. Has-a relationships should be implemented using inheritance.
C. Has-a relationships can be implemented using instance variables.
D. Is-a relationships can be implemented using the extends keyword.
E. Is-a relationships can be implemented using the implements keyword.
F. The relationship between Movie and Actress is an example of an is-a relationship.
G. An array or a collection can be used to implement a one-to-many has-a relationship.
Answer: CDEG
Question 160
Which two are true about has-a and is-a relationships? (Choose two.)
A. Inheritance represents an is-a relationship.
B. Inheritance represents a has-a relationship.
C. Interfaces must be used when creating a has-a relationship.
D. Instance variables can be used when creating a has-a relationship.
Answer: AD
Question 161
Given:
10. interface Jumper { public void jump(); }
......
20. class Animal {}
......
30. class Dog extends Animal {
31. Tail tail;
32. }
......
40. class Beagle extends Dog implements Jumper {
41. public void jump() { }
42. }
.......
50. class Cat implements Jumper {
51. public void jump() { }
52. }
Which three are true? (Choose three.)
A. Cat is-a Animal
B. Cat is-a Jumper
C. Dog is-a Animal
D. Dog is-a Jumper
E. Cat has-a Animal
F. Beagle has-a Tail
G. Beagle has-a Jumper
Answer: BCF
Question 162
Given:
1. import java.util.*;
2. public class Example {
3. public static void main(String[] args) {
4. // insert code here
5. set.add(new integer(2));
6. set.add(new integer(l));
7. System.out.println(set);
8. }
9. }
Which code, inserted at line 4, guarantees that this program will
output [1, 2]?
A. Set set = new TreeSet();
B. Set set = new HashSet();
C. Set set = new SortedSet();
D. List set = new SortedList();
E. Set set = new LinkedHashSet();
Answer: A
Question 163
Given:
1. import java.util.*;
2. public class PQ {
3. public static void main(String[] args) {
4. PriorityQueue pq = new PriorityQueue();
5. pq.add(”carrot”);
6. pq.add(”apple”);
7. pq.add(”banana”);
8. System.out.println(pq.poll() +”:” + pq.peek());
9. }
10. }
What is the result?
A. apple:apple
B. carrot:apple
C. apple:banana
D. banana:apple
E. carrot:carrot
F. carrot:banana
Answer: C
Question 164
Given:
1. import java.util.*;
2. public class WrappedString {
3. private String s;
4. public WrappedString(String s) { this.s = s; }
5. public static void main(String[] args) {
6. HashSet hs = new HashSet();
7. WrappedString ws1 = new WrappedString(”aardvark”);
8. WrappedString ws2 = new WrappedString(”aardvark”);
9. String s1 = new String(”aardvark”);
10. String s2 = new String(”aardvark”);
11. hs.add(ws1); hs.add(ws2); hs.add(s1); hs.add(s2);
12. System.out.println(hs.size()); } }
What is the result?
A. 0
B. 1
C. 2
D. 3
E. 4
F. Compilation fails.
G. An exception is thrown at runtime.
Answer: D
Question 165
Click the Exhibit button.
1. import java.util.*;
2. public class TestSet {
3. enum Example { ONE, TWO, THREE }
4. public static void main(String[] args) {
5. Collection coll = new ArrayList();
6. coll.add(Example.THREE);
7. coll.add(Example.THREE);
8. coll.add(Example.THREE);
9. coll.add(Example.TWO);
10. coll.add(Example.TWO);
11. coll.add(Example.ONE);
12. Set set = new HashSet(coll);
13. }
14. }
Which statement is true about the set variable on line 12?
A. The set variable contains all six elements from the coll collection, and the order is guaranteed to be preserved.
B. The set variable contains only three elements from the coll collection, and the order is guaranteed to be preserved.
C. The set variable contains all six elements from the coil collection, but the order is NOT guaranteed to be preserved.
D. The set variable contains only three elements from the coil collection, but the order is NOT guaranteed to be preserved.
Answer: D
Question 166
Given:
1. public class Score implements Comparable {
2. private int wins, losses;
3. public Score(int w, int 1) { wins = w; losses = 1; }
4. public int getWins() { return wins; }
5. public int getLosses() { return losses; }
6. public String toString() {
7. return “”;
8. }
9. // insert code here
10. }
Which method will complete this class?
A. public int compareTo(Object o) {/*mode code here*/}
B. public int compareTo(Score other) {/*more code here*/}
C. public int compare(Score s1,Score s2){/*more code here*/}
D. public int compare(Object o1,Object o2){/*more code here*/}
Answer: B
Question 167
A programmer has an algorithm that requires a java.util.List that provides an efficient implementation of add(0,object), but does NOT need to support quick random access. What supports these requirements?
A. java.util.Queue
B. java.util.ArrayList
C. java.util.LinearList
D. java.util.LinkedList
Answer: D
Question 168
Given:
11. public class Person {
12. private String name, comment;
13. private int age;
14. public Person(String n, int a, String c) {
15. name = n; age = a; comment = c;
16. }
17. public boolean equals(Object o) {
18. if(! (o instanceof Person)) return false;
19, Person p = (Person)o;
20. return age == p.age && name.equals(p.name);
21. }
22. }
What is the appropriate definition of the hashCode method in class
Person?
A. return super.hashCode();
B. return name.hashCode() + age * 7;
C. return name.hashCode() + comment.hashCode() /2;
D. return name.hashCode() + comment.hashCode() / 2 - age * 3;
Answer: B
Question 169
Given:
11. public class Key {
12. private long id1;
13. private long 1d2;
14.
15. // class Key methods
16. }
A programmer is developing a class Key, that will be used as a key in a standard java.util.HashMap. Which two methods should be overridden to assure that Key works correctly as a key? (Choose two.)
A. public int hashCode()
B. public boolean equals(Key k)
C. public int compareTo(Object o)
D. public boolean equals(Object o)
E. public boolean compareTo(Key k)
Answer: AD
Question 170
Given:
11. public class Person {
12. private name;
13. public Person(String name) {
14. this.name = name;
15. }
16. public boolean equals(Object o) {
17. if( !o instanceof Person ) return false;
18. Person p = (Person) o;
19. return p.name.equals(this.name);
20. }
21. }
Which is true?
A. Compilation fails because the hashCode method is not overridden.
B. A HashSet could contain multiple Person objects with the same name.
C. All Person objects will have the same hash code because the hashCode method is not overridden.
D. If a HashSet contains more than one Person object with name=”Fred”, then removing another Person, also with name=”Fred”, will remove them all.
Answer: B
Question 171
Given:
1. public class Person {
2. private String name;
3. public Person(String name) { this.name = name; }
4. public boolean equals(Person p) {
5. return p.name.equals(this.name);
6. }
7. }
Which is true?
A. The equals method does NOT properly override the Object.equals method.
B. Compilation fails because the private attribute p.name cannot be accessed in line 5.
C. To work correctly with hash-based data structures, this class must also implement the hashCode method.
D. When adding Person objects to a java.util.Set collection, the equals method in line 4 will prevent duplicates.
Answer: A
Question 172
Which two statements are true about the hashCode method? (Choose two.)
A. The hashCode method for a given class can be used to test for object equality and object inequality for that class.
B. The hashCode method is used by the java.util.SortedSet collection class to order the elements within that set.
C. The hashCode method for a given class can be used to test for object inequality, but NOT object equality, for that class.
D. The only important characteristic of the values returned by a hashCode method is that the distribution of values must follow a Gaussian distribution.
E. The hashCode method is used by the java.util.HashSet collection class to group the elements within that set into hash buckets for swift retrieval.
Answer: CE
Question 173
Given:
enum Example { ONE, TWO, THREE }
Which is true?
A. The expressions (ONE == ONE) and ONE.equals(ONE) are both guaranteed to be true.
B. The expression (ONE < TWO) is guaranteed to be true and ONE.compareTo(TWO) is guaranteed to be less than one.
C. The Example values cannot be used in a raw java.util.HashMap; instead, the programmer must use a java.util.EnumMap.
D. The Example values can be used in a java.util.SortedSet, but the set will NOT be sorted because enumerated types do NOT implement java.lang.Comparable.
Answer: A
Question 174
Click the Exhibit button.
1. import java.util.*;
2. class KeyMaster {
3. public int i;
4. public KeyMaster(int i) { this.i = i; }
5. public boolean equals(Object o) { return i == ((KeyMaster)o).i; }
6. public int hashCode() { return i; }
7. }
8. public class MapIt {
9. public static void main(String[] args) {
10. Set set = new HashSet();
11. KeyMaster k1 = new KeyMaster(1);
12. KeyMaster k2 = new KeyMaster(2);
13. set.add(k1); set.add(k1);
14. set.add(k2); set.add(k2);
15. System.out.print(set.size() + “:”);
16. k2.i = 1;
17. System.out.print(set.size() + “:”);
18. set.remove(k1);
19. System.out.print(set.size() + “:”);
20. set.remove(k2);
21. System.out.print(set.size());
22. }
23. }
What is the result?
A. 4:4:2:2
B. 4:4:3:2
C. 2:2:1:0
D. 2:2:0:0
E. 2:1:0:0
F. 2:2:1:1
G. 4:3:2:1
Answer: F
Question 175
Given:
1. import java.util.*;
2. public class Test {
3. public static void main(String[] args) {
4. List strings = new ArrayList();
5. // insert code here
6. }
7. }
Which four, inserted at line 5, will allow compilation to succeed? (Choose four.)
A. String s = strings.get(0);
B. Iterator i1 = strings.iterator();
C. String[] array1 = strings.toArray();
D. Iterator i2 = strings.iterator();
E. String[] array2 = strings.toArray(new String[1]);
F. Iterator i3 = strings.iterator();
Answer: ABDE
Question 176
Given:
1. import java.util.*;
2. public class Old {
3. public static Object get()(List list) {
4. return list.get(0);
5. }
6. }
Which three will compile successfully? (Choose three.)
A. Object o = Old.get0(new LinkedList());
B. Object o = Old.get0(new LinkedList());
C. String s = Old.getfl(new LinkedList());
D. Object o = Old.get0(new LinkedList());
E. String s = (String)Old.get0(new LinkedList());
Answer: ADE
Question 177
Given:
11. public static void append(List list) { list.add(”0042”); }
12. public static void main(String[] args) {
13. List intList = new ArrayList();
14. append(intList);
15. System.out.println(intList.get(0));
16. }
What is the result?
A. 42
B. 0042
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
E. Compilation fails because of an error in line 14.
Answer: B
Question 178
Given a pre-generics implementation of a method:
11. public static int sum(List list) {
12. int sum = 0;
13. for ( Iterator iter = list.iterator(); iter.hasNext(); ) {
14. int i = ((Integer)iter.next()).intValue();
15. sum += i;
16. }
17. return sum;
18. }
Which three changes must be made to the method sum to use generics? (Choose three.)
A. remove line 14
B. replace line 14 with “int i = iter.next();”
C. replace line 13 with “for (int i : intList) {“
D. replace line 13 with “for (Iterator iter : intList) {“
E. replace the method declaration with “sum(List intList)”
F. replace the method declaration with “sum(List intList)”
Answer: ACF
Question 179
Given:
classA {}
class B extends A {}
class C extends A {}
class D extends B {}
Which three statements are true? (Choose three.)
A. The type List is assignable to List.
B. The type List is assignable to List.
C. The type List is assignable to List.
D. The type List is assignable to List.
E. The type List is assignable to List.
F. The type List is assignable to any List reference.
G. The type List is assignable to List.
Answer: CDG
Question 180
Given:
11. public void addStrings(List list) {
12. list.add(”foo”);
13. list.add(”bar”);
14. }
What must you change in this method to compile without warnings?
A. add this code after line 11:
list = (List) list;
B. change lines 12 and 13 to:
list.add(”foo”);
list.add(”bar”);
C. change the method signature on line 11 to:
public void addStrings(List list) {
D. change the method signature on line 11 to:
public void addStrings(List list) {
E. No changes are necessary. This method compiles without warnings.
Answer: D
Question 181
Given:
1. public class Test {
2. public T findLarger(T x, T y) {
3. if(x.compareTo(y) > 0) {
4. return x;
5. } else {
6. return y;
7. }
8. }
9. }
and:
22. Test t = new Test();
23. // insert code here
Which two will compile without errors when inserted at line 23?
(Choose two.)
A. Object x = t.findLarger(123, “456”);
B. int x = t.findLarger(123, new Double(456));
C. int x = t.findLarger(123, new Integer(456));
D. int x = (int) t.findLarger(new Double(123), new Double(456));
Answer: AC
Question 182
Given:
11. // insert code here
12. private N min, max;
13. public N getMin() { return min; }
14. public N getMax() { return max; }
15. public void add(N added) {
16. if (min == null || added.doubleValue()
17. min = added;
18. if (max == null ||added.doubleValue() > max.doubleValue())
19. max = added;
20. }
21. }
Which two, inserted at line 11, will allow the code to compile? (Choose
two.)
A. public class MinMax {
B. public class MinMax {
C. public class MinMax {
D. public class MinMax {
E. public class MinMax {
F. public class MinMax {
Answer: DF
Question 183
A programmer must create a generic class MinMax and the type parameter of MinMax must implement Comparable. Which implementation of MinMax will compile?
A. class MinMax> {
E min=null;
E max=null;
public MinMax() { }
public void put(E value) { /* store min or max */ }
}
B. class MinMax> {
E min=null;
E max=null;
public MinMax() { }
public void put(E value) { /* store min or max */ }
}
C. class MinMax> {
E min = null;
E max = null;
public MinMax() { }
public void put(E value) { /* store min or max */ }
}
D. class MinMax> {
E min = null;
E max = null;
public MinMax() { }
public void put(E value) { /* store min or max */ }
}
Answer: A
Question 184
Given:
1. public class Drink implements Comparable {
2. public String name;
3. public int compareTo(Object o) {
4. return 0;
5. }
6. }
and:
20. Drink one = new Drink();
21. Drink two = new Drink();
22. one.name= “Coffee”;
23. two.name= “Tea”;
23. TreeSet set = new TreeSet();
24. set.add(one);
25. set.add(two);
A programmer iterates over the TreeSet and prints the name of each Drink object.
What is the result?
A. Tea
B. Coffee
C. Coffee Tea
D. Compilation fails.
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: B
Question 185
Given:
11. List list = // more code here
12. Collections.sort(list, new MyComparator());
Which code will sort this list in the opposite order of the sort in line 12?
A. Collections.reverseSort(list, new MyComparator());
B. Collections.sort(list, new MyComparator());
list.reverse();
C. Collections.sort(list, new InverseComparator(
new MyComparator()));
D. Collections.sort(list, Collections.reverseOrder(
new MyComparator()));
Answer: D
Question 186
Given:
int[] myArray=newint[] {1, 2,3,4, 5};
What allows you to create a list from this array?
A. List myList = myArray.asList();
B. List myList = Arrays.asList(myArray);
C. List myList = new ArrayList(myArray);
D. List myList = Collections.fromArray(myArray);
Answer: B
Question 187
Given:
13. public static void search(List list) {
14. list.clear();
15. list.add(”b”);
16. list.add(”a”);
17. list.add(”c”);
18. System.out.println(Collections.binarySearch(list, “a”));
19. }
What is the result of calling search with a valid List implementation?
A. 0
B. 1
C. 2
D. a
E. b
F. c
G. The result is undefined.
Answer: G
Question 188
Given:
1. import java.util.*;
2.
3. public class LetterASort {
4. public static void main(String[] args) {
5. ArrayList strings = new ArrayList();
6. strings.add(’aAaA”);
7. strings.add(”AaA”);
8. strings.add(’aAa”);
9. strings.add(”AAaa”);
10. Collections.sort(strings);
11. for (String s: strings) { System.out.print(s + “ “); }
12. }
13. }
What is the result?
A. Compilation fails.
B. aAaA aAa AAaa AaA
C. AAaa AaA aAa aAaA
D. AaA AAaa aAaA aAa
E. aAa AaA aAaA AAaa
F. An exception is thrown at runtime.
Answer: C
Question 189
Given:
ArrayList a = new ArrayList();
containing the values {“1”, “2”, “3”, “4”, “5”, “6”, “7”, “8”}
Which code will return 2?
A. Collections. sort(a, a.reverse());
int result = Collections.binarySearch(a, “6”);
B. Comparator c = Collections.reverseOrder();
Collections.sort(a, c);
int result = Collections.binarySearch(a, “6”);
C. Comparator c = Collections.reverseOrder();
Collections.sort(a, c);
int result = Collections.binarySearch(a, “6”,c);
D. Comparator c = Collections.reverseOrder(a);
Collections.sort(a, c);
int result = Collections.binarySearch(a, “6”,c);
E. Comparator c = new InverseComparator(new Comparator());
Collections.sort(a);
int result = Collections.binarySearch(a, “6”,c);
Answer: C
Question 190
Given:
34. HashMap props = new HashMap();
35. props.put(”key45”, “some value”);
36. props.put(”key12”, “some other value”);
37. props.put(”key39”, “yet another value”);
38. Set s = props.keySet();
39. // insert code here
What, inserted at line 39, will sort the keys in the props HashMap?
A. Arrays.sort(s);
B. s = new TreeSet(s);
C. Collections.sort(s);
D. s = new SortedSet(s);
Answer: B
Question 191
Given classes defined in two different files:
1. package util;
2. public class BitUtils {
3. public static void process(byte[]) { /* more code here */ }
4. }
1. package app;
2. public class SomeApp {
3. public static void main(String[] args) {
4. byte[] bytes = new byte[256];
5. // insert code here
6. }
7. }
What is required at line 5 in class SomeApp to use the process method
of BitUtils?
A. process(bytes);
B. BitUtils.process(bytes);
C. util.BitUtils.process(bytes);
D. SomeApp cannot use methods in BitUtils.
E. import util.BitUtils.*; process(bytes);
Answer: C
Question 192
Given classes defined in two different files:
1. package util;
2. public class BitUtils {
3. private static void process(byte[] b) { }
4. }
1. package app;
2. public class SomeApp {
3. public static void main(String[] args) {
4. byte[] bytes = new byte[256];
5. // insert code here
6. }
7. }
What is required at line 5 in class SomeApp to use the process method
of BitUtils?
A. process(bytes);
B. BitUtils.process(bytes);
C. app.BitUtils.process(bytes);
D. util.BitUtils.process(bytes);
E. import util.BitUtils. *; process(bytes);
F. SomeApp cannot use the process method in BitUtils.
Answer: F
Question 193
Given classes defined in two different files:
1. package packageA;
2. public class Message {
3. String getText() { return “text”; }
4. }
and:
1. package packageB;
2. public class XMLMessage extends packageA.Message {
3. String getText() { return “text”; }
4. public static void main(String[] args) {
5. System.out.println(new XMLMessage().getText());
6. }
7. }
What is the result of executing XMLMessage.main?
A. text
B. <msg>text</msg>
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 2 of XMLMessage.
E. Compilation fails because of an error in line 3 of XMLMessage.
Question 194
Given a file GrizzlyBear.java:
1. package animals.mammals;
2.
3. public class GrizzlyBear extends Bear {
4. void hunt() {
5. Salmon s = findSalmon();
6. s.consume();
7. }
8. }
and another file, Salmon.java:
1. package animals.fish;
2.
3. public class Salmon extends Fish {
4. void consume() { /* do stuff */ }
5. }
Assume both classes are defined in the correct directories for theft
packages, and that the Mammal class correctly defines the
findSalmon() method. Which two changes allow this code to compile
correctly? (Choose two.)
A. add public to the start of line 4 in Salmon.java
B. add public to the start of line 4 in GrizzlyBear.java
C. add import animals.mammals.*; at line 2 in Salmon.java
D. add import animals.fish.*; at line 2 in GrizzlyBear.java
E. add import animals.fish.Salmon.*; at line 2 in GrizzlyBear.java
F. add import animals.mammals.GrizzlyBear.*;at line 2 in Salmon.java
Answer: AD
Question 195
Given a class Repetition:
1. package utils;
2.
3. public class Repetition {
4. public static String twice(String s) { return s + s; }
5. }
and given another class Demo:
1. // insert code here
2.
3. public class Demo {
4. public static void main(String[] args) {
5. System.out.println(twice(”pizza”));
6. }
7. }
Which code should be inserted at line 1 of Demo.java to compile and
run Demo to print “pizzapizza”?
A. import utils.*;
B. static import utils.*;
C. import utils.Repetition.*;
D. static import utils.Repetition. *;
E. import utils.Repetition.twice();
F. import static utils.Repetition.twice;
G. static import utils.Repetition.twice;
Answer: F
Question 196
Given:
11. interface DeclareStuff{
12. public static final int EASY = 3;
13. void doStuff(int t); }
14. public class TestDeclare implements DeclareStuff {
15. public static void main(String [] args) {
16. int x=5;
17. new TestDeclare().doStuff(++x);
18. }
19. void doStuff(int s) {
20. s += EASY + ++s;
21. System.out.println(”s “ + s);
22. }
23. }
What is the result?
A. s 14
B. s 16
C. s 10
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
Question 197
Given:
1. interface DoStuff2 {
2. float getRange(int low, int high); }
3.
4. interface DoMore {
5. float getAvg(int a, int b, int c); }
6.
7. abstract class DoAbstract implements DoStuff2, DoMore { }
8.
9. class DoStuff implements DoStuff2 {
10. public float getRange(int x, int y) { return 3.14f; } }
11.
12. interface DoAll extends DoMore {
13. float getAvg(int a, int b, int c, int d); }
What is the result?
A. The file will compile without error.
B. Compilation fails. Only line 7 contains an error.
C. Compilation fails. Only line 12 contains an error.
D. Compilation fails. Only line 13 contains an error.
E. Compilation fails. Only lines 7 and 12 contain errors.
F. Compilation fails. Only lines 7 and 13 contain errors.
G. Compilation fails. Lines 7, 12, and 13 contain errors.
Answer: A
Question 198
Given:
11. public class Counter {
12. public static void main(String[] args) {
13. int numArgs = /* insert code here */;
14. }
15. }
and the command line:
java Counter one fred 42
Which code, inserted at line 13, captures the number of arguments
passed into the program?
A. args.count
B. args.length
C. args.count()
D. args.length()
E. args.getLength()
Answer: B
Question 199
Given a correctly compiled class whose source code is:
1. package com.sun.sjcp;
2. public class Commander {
3. public static void main(String[] args) {
4. // more code here
5. }
6. }
Assume that the class file is located in /foo/com/sun/sjcp/, the current
directory is /foo/, and that the classpath contains “.“ (current
directory).
Which command line correctly runs Commander?
A. java Commander
B. java com. sim. sjcp.Commander
C. java com/sun/sjcp/Commander
D. java -cp com.sun.sjcp Commander
E. java -cp com/sun/sjcp Commander
Answer: B
Question 200
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(” doStuffx = “+ x++);
25. }
26. }
What is the result?
A. Compilation fails.
B. An exception is thrown at runtime.
C. doStuffx = 6 main x = 6
D. doStuffx = 6 main x = 7
E. doStuffx = 7 main x = 6
F. doStuffx = 7 main x = 7
Answer: B
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