单项选择题
import java.util.*;
public class WrappedString {
private String s;
public WrappedString(String s) { this.s = s; }
public static void main(String[] args) {
HashSet
A. 0
B. 1
C. 2
D. 3
E. 4
F. Compilation fails.
G. An exception is thrown at runtime.
相关考题
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单项选择题
import java.util.*; public class PQ { public static void main(String[] args) { PriorityQueue pq = new PriorityQueue(); pq.add(”carrot”); pq.add(”apple”); pq.add(”banana”); System.out.println(pq.poll() +”:” + pq.peek()); } } What is the result?()
A. apple:apple
B. carrot:apple
C. apple:banana
D. banana:apple
E. carrot:carrot
F. carrot:banana -
单项选择题
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(); -
多项选择题
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?()
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
