Java和C++在细节上的差异(四) - JAVA

ArrayList list = newArrayList();
3 list.add("Monday");
4 list.add("Tuesdag");
5 list.add("Wednesday");
6 Iterator iterator = null;
7 iterator = list.iterator();
8 //while
9 while(iterator.hasNext()) {
10 String element = iterator.next();
11 System.out.println(element);
12 }
13 //for
14 for(iterator = list.iterator(); iterator.hasNext();) {
15 String element = iterator.next();
16 System.out.println(element);
17 }
18 //for each
19 for(String element : list) {
20 System.out.println(element);
21 }
22 }
23
24 publicstaticvoidshowSetAndGet() {
25 ArrayList nums = newArrayList();
26 nums.clear();
27 nums.add("One");
28 nums.add("Two");
29 nums.add("Three");
30 System.out.println(nums);
31 nums.set(0, "Uno");
32 nums.set(1, "Dos");
33 nums.set(2, "Tres");
34 for(inti = 0; i < nums.size(); ++i)
35 System.out.println(nums.get(i));
36 }
37
38 publicstaticvoidshowRemoveAndSize() {
39 ArrayList al = newArrayList();
40 System.out.println("Initial size of al: " + al.size());
41 al.add("C");
42 al.add("A");
43 al.add("E");
44 al.add("B");
45 al.add(1, "A2");
46 System.out.println("Size of al after additions: " + al.size());
47 System.out.println("Contents of al: " + al);

48 al.remove("F");
49 al.remove(2);
50 System.out.println("Size of al after deletions: " + al.size());
51 System.out.println("Contents of al: " + al);
52 Iterator it = al.iterator();
53 //Notes：remove() must be called after next()
54 it.next();
55 it.remove();
56 System.out.println("Size of al after deletions: " + al.size());
57 System.out.println("Contents of al: " + al);
58 }
59
60 publicstaticvoidshowSubListAndCopyToArray() {
61 ArrayList arrayList = newArrayList();
62 arrayList.add("1");
63 arrayList.add("2");
64 arrayList.add("3");
65 arrayList.add("4");
66 arrayList.add("5");
67 List lst = arrayList.subList(1, 3);
68 for(inti = 0; i < lst.size(); i++)
69 System.out.println(lst.get(i));
70 // remove one element from sub list
71 String obj = lst.remove(0);
72 System.out.println(obj + " is removed");
73 for(String str: arrayList)
74 System.out.println(str);
75 //get object array with normal method
76 Object[] objArray = arrayList.toArray();
77 for(Object obj1 : objArray)
78 System.out.println(obj1);
79 //get object array with generic method
80 String[] strArray = arrayList.toArray(newString[0]);
81 for(String str : strArray)
82 System.out.println(str);
83 }
84
85 publicstaticvoidshowListIterator() {
86 ArrayList aList = newArrayList();
87 aList.add("1");
88 aList.add("2");
89 aList.add("3");
90 aList.add("4");
91 aList.add("5");
92
93

Java和C++在细节上的差异(四)(五)