map存储数据，键值对

已知字符串“adhflkalkfdhasdkhflsa”，统计每个字符出现的次数，使用map存储，字符为键，次数为值。

大概写下伪代码

String str = “adhflkalkfdhasdkhflsa”;
HashMap<char,Int> map = new HashMap<char,Int>();
for(int i=0;i<str.length;i++){
  char temp = str.charAt(i);
  if(map.containsKey(temp)){
    map.put(temp,map.get(temp)+1);  
  }else{
    map.put(temp,1);  
  }
}


 String str = "adhflkalkfdhasdkhflsa";
        Map<String,Integer> map = new HashMap<>();

        for (int i = 0,index = str.length();i < index;i++) {
            char temp = str.charAt(i);
            if (map.containsKey(String.valueOf(temp))) {
                map.put(temp +"",map.get(String.valueOf(temp)) + 1);
            }else {
                map.put(temp +"",1);
            }
        }
        System.out.println(map);


import java.util.HashMap;
import java.util.Map;

public class Test {
    private Map<Character, Integer> countCharacter(String str) {
        Map<Character, Integer> map = new HashMap<>();
        for (char c : str.toCharArray()) {
            map.put(c, map.getOrDefault(c, 0) + 1);
        }
        return map;
    }

    public static void main(String[] args) {
        System.out.println(new Test().countCharacter("adhflkalkfdhasdkhflsa"));
    }
}

运行结果示例：

img