1 import java.util.HashMap;
 2 import java.util.Map;
 3 import java.util.Scanner;
 4 
 5 /**
 6  * 目标 : 输出一个字符串中每个字符出现的次数.(经典面试题).
 7  * 
 8  * @author Administrator
 9  *
10  */
11 public class MapDemo01 {
12 
13     public static void main(String[] args) {
14         // TODO Auto-generated method stub
15 //        1 键盘录入一个字符串
16         Scanner name = new Scanner(System.in);
17         System.out.println("请您输入一个字符串: ");
18         String contest = name.nextLine();
19 //        2 定义map集合,
20         Map<Character, Integer> ele = new HashMap<>();
21 //        3 遍历字符串中的每一个字符
22 //        datas=aabbccddaa123
23         for (int i = 0; i < contest.length(); i++) {
24             char ch = contest.charAt(i);
25             if (ele.containsKey(ch)) {
26                 ele.put(ch, ele.get(ch) + 1);
27             } else {
28                 ele.put(ch, 1);
29             }
30         }
31         System.out.println("结果为: " + ele);
32     }
33 
34 }