实例代码：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
public class Test {
public static void main(String[] args) {
int a = 0, b = 0, c = 0;
// 第一种:通过Map.keySet()遍历Map及将Map转化为二维数组
Map<String, String> map1 = new HashMap<String, String>();
map1.put("012013012013", "张三");
map1.put("012013012014", "张四");
String[][] group1 = new String[map1.size()][2];
System.out.println("第一种:通过Map.keySet()遍历map1的key和value");
for (String key : map1.keySet()) {
System.out.println("key = " + key + " and value = " + map1.get(key));
group1[a][0] = key;
group1[a][1] = map1.get(key);
a++;
}
System.out.println("map1.size()为：" + map1.size() + ",a为：" + a + "，group1数组的长度为：" + group1.length);
System.out.println("----------------------------------------------------");
for(int n = 0; n < group1.length; n++) {
System.out.println("key = " + group1[n][0] + " and value = " + group1[n][1]);
}
// 第二种:通过Map.entrySet()使用iterator()遍历Map及将Map转化为二维数组
Map<String, String> map2 = new HashMap<String, String>();
map2.put("112013012013", "李三");
map2.put("112013012014", "李四");
System.out.println("\n" + "第二种:通过Map.entrySet()使用iterator()遍历map2的key和value");
Iterator<Map.Entry<String, String>> iterator = map2.entrySet().iterator();
String[][] group2 = new String[map2.size()][2];
while (iterator.hasNext()) {
Map.Entry<String, String> entry = iterator.next();
System.out.println("key = " + entry.getKey() + " and value = " + entry.getValue());
group2[b][0] = entry.getKey();
group2[b][1] = entry.getValue();
b++;
}
System.out.println("map2.size()为：" + map2.size() + ",b为：" + b + "，group2数组的长度为：" + group2.length);
System.out.println("----------------------------------------------------");
for(int n = 0; n < group2.length; n++) {
System.out.println("key = " + group2[n][0] + " and value = " + group2[n][1]);
}
// 第三种:通过Map.entrySet()遍历遍历Map及将Map转化为二维数组
Map<String, String> map = new HashMap<String, String>();
map.putAll(map1);
map.putAll(map2);
String[][] group3 = new String[map.size()][2];
System.out.println("\n" + "第三种:通过Map.entrySet()遍历map的key和value ");
for (Map.Entry<String, String> entry : map.entrySet()) {
System.out.println("key = " + entry.getKey() + " and value = " + entry.getValue());
group3[c][0] = entry.getKey();
group3[c][1] = entry.getValue();
c++;
}
System.out.println("map.size()为：" + map.size() + ",c为：" + c + "，group3数组的长度为：" + group3.length);
System.out.println("----------------------------------------------------");
for(int n = 0; n < group3.length; n++) {
System.out.println("key = " + group3[n][0] + " and value = " + group3[n][1]);
}
}
}
|
输出结果为：
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
第一种:通过Map.keySet()遍历map1的key和value
key = 012013012013 and value = 张三
key = 012013012014 and value = 张四
map1.size()为：2,a为：2，group1数组的长度为：2
----------------------------------------------------
key = 012013012013 and value = 张三
key = 012013012014 and value = 张四
第二种:通过Map.entrySet()使用iterator()遍历map2的key和value
key = 112013012014 and value = 李四
key = 112013012013 and value = 李三
map2.size()为：2,b为：2，group2数组的长度为：2
----------------------------------------------------
key = 112013012014 and value = 李四
key = 112013012013 and value = 李三
第三种:通过Map.entrySet()遍历map的key和value
key = 112013012014 and value = 李四
key = 112013012013 and value = 李三
key = 012013012013 and value = 张三
key = 012013012014 and value = 张四
map.size()为：4,c为：4，group3数组的长度为：4
----------------------------------------------------
key = 112013012014 and value = 李四
key = 112013012013 and value = 李三
key = 012013012013 and value = 张三
key = 012013012014 and value = 张四
|
如有疑问请留言或者到本站社区交流讨论，大家共同进步，感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！
原文链接：http://blog.csdn.net/caihuangshi/article/details/17552933