1 package com.zlh;
2
3 import java.util.ArrayList;
4 import java.util.HashMap;
5 import java.util.Iterator;
6 import java.util.Map;
7 import java.util.Map.Entry;
8 import java.util.Set;
9
10 public class TravelseDemo {
11
12 public static void main(String[] args) {
13 // 数组遍历
14 System.out.println("1 数组遍历");
15 String[] str1 = { "数", "组", "遍", "历" };
16 arrayTravelse(str1);
17 System.out.println("===================");
18 // 字符串遍历
19 System.out.println("2 字符串遍历");
20 String str2 = "字符串遍历";
21 stringTravelse(str2);
22 System.out.println("===================");
23 // list遍历
24 ArrayList<String> list = new ArrayList<String>();
25 list.add("集");
26 list.add("合");
27 list.add("遍");
28 list.add("历");
29 // list遍历-for-each
30 System.out.println("3 list遍历-for-each");
31 forTravelse(list);
32 System.out.println("===================");
33 // list遍历-迭代器
34 System.out.println("4 list遍历-迭代器");
35 iteratorTravelse(list);
36 System.out.println("===================");
37 // map遍历
38 Map<String, Integer> map = new HashMap<String, Integer>();
39 map.put("jack", 1);
40 map.put("tom", 2);
41 map.put("jerry", 3);
42 // map遍历-for-each与keySet
43 System.out.println("5 map遍历-for-each与keySet");
44 forKeySetTravelse(map);
45 System.out.println("===================");
46 // map遍历-迭代器与keySet
47 System.out.println("6 map遍历-迭代器与keySet");
48 iteratorKeySetTravelse(map);
49 System.out.println("===================");
50 // map遍历-for-each与entry
51 System.out.println("7 map遍历-for-each与entry");
52 forEntryTravelse(map);
53 System.out.println("===================");
54 // map遍历-迭代器与entry
55 System.out.println("8 map遍历-迭代器与entry");
56 iteratorEntryTravelse(map);
57 }
58
59 // 数组遍历
60 private static void arrayTravelse(String[] str) {
61 for (int i = 0; i < str.length; i++) {
62 String j = str[i];
63 System.out.print(j + " ");
64 }
65 System.out.println();
66 }
67
68 // 字符串遍历
69 private static void stringTravelse(String str) {
70 for (int i = 0; i < str.length(); i++) {
71 char c = str.charAt(i);
72 System.out.print(c + " ");
73 }
74 System.out.println();
75 }
76
77 // for-each循环遍历
78 private static void forTravelse(ArrayList<String> list) {
79 for (String str : list) {
80 System.out.print(str + " ");
81 }
82 System.out.println();
83 }
84
85 // 迭代器遍历
86 private static void iteratorTravelse(ArrayList<String> list) {
87 Iterator<String> it = list.iterator();
88 while (it.hasNext()) {
89 String next = it.next();
90 System.out.print(next + " ");
91 }
92 System.out.println();
93 }
94
95 // map遍历-for-each与keySet
96 private static void forKeySetTravelse(Map<String, Integer> map) {
97 Set<String> set = map.keySet();
98 for (String key : set) {
99 Integer value = map.get(key);
100 System.out.print(key + ":" + value + " ");
101 }
102 System.out.println();
103 }
104
105 // map遍历-迭代器与keySet
106 private static void iteratorKeySetTravelse(Map<String, Integer> map) {
107 Set<String> set = map.keySet();
108 Iterator<String> it = set.iterator();
109 while(it.hasNext()) {
110 String key = it.next();
111 Integer value = map.get(key);
112 System.out.print(key + ":" + value + " ");
113 }
114 System.out.println();
115 }
116
117 // map遍历-for-each与entry
118 private static void forEntryTravelse(Map<String, Integer> map) {
119 Set<Entry<String, Integer>> set = map.entrySet();
120 for (Map.Entry<String, Integer> entry : set) {
121 String key = entry.getKey();
122 Integer value = entry.getValue();
123 System.out.print(key + ":" + value + " ");
124 }
125 System.out.println();
126 }
127
128 // map遍历-迭代器与entry
129 private static void iteratorEntryTravelse(Map<String, Integer> map) {
130 Set<Entry<String, Integer>> set = map.entrySet();
131 Iterator<Entry<String, Integer>> it = set.iterator();
132 while (it.hasNext()) {
133 Entry<String, Integer> en = it.next();
134 String key = en.getKey();
135 Integer value = en.getValue();
136 System.out.print(key + ":" + value + " ");
137 }
138 System.out.println();
139 }
140 }
