SCJP題庫第196題

 

Given:

34. HashMap props = new HashMap();

35. props.put("key45", "some value");

36. props.put("keyl2", "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);

Ans: B

解說:

TreeSet是一個排序樹