单项选择题
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);
相关考题
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单项选择题
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); -
单项选择题
import java.util.*; public class LetterASort { public static void main(String[] args) { ArrayList strings = new ArrayList(); strings.add(aAaA”); strings.add(”AaA”); strings.add(aAa”); strings.add(”AAaa”); Collections.sort(strings); for (String s: strings) { System.out.print(s + “ “); } } } 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. -
单项选择题
public static void search(List list) { list.clear(); list.add(”b”); list.add(”a”); list.add(”c”); System.out.println(Collections.binarySearch(list, “a”)); } What is the result of calling search with a valid List implementation?()
A.0
B.1
C.a
D.b
E.c
F.The result is undefined.
