1、分析

2、代码实现

package Demo016;import java.util.HashMap;
import java.util.Scanner;public class demo010MapTest {public static void main(String[] args) {Scanner sc=new Scanner(System.in);System.out.println("请输入一个字符串:");String s = sc.next();HashMap<Character,Integer> map=new HashMap<>();for(char key:s.toCharArray()){//遍历数组if(map.containsKey(key)){//Key存在Integer value1 = map.get(key);value1++;map.put(key,value1);}else{//Key不存在map.put(key,1);}}//遍历集合for(Character set:map.keySet()){Integer value2 = map.get(set);System.out.println(set+"="+value2);}}
}

3、运行结果