Given the code fragment:
Map<Integer, String> books = new TreeMap<>();
books.put(1007, "A");
books.put(1002, "C");
books.put(1001, "B");
books.put(1003, "B");
System.out.println(books);
What is the result?
A.
{1007 = A, 1002 = C, 1001 = B, 1003 = B}
B.
{1001 = B, 1002 = C, 1003 = B, 1007 = A}
C.
{1002 = C, 1003 = B, 1007 = A}
D.
{1007 = A, 1001 = B, 1003 = B, 1002 = C}
題解
TreeMap繼承SortedMap，會自動排序元素的key。所以這題答案是選項B。