习题：字符串中的字符统计 JAVA

字符串中的字符统计

package day20200820;

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

public class Demo01 {
    
    
	public static void main(String[] args) {
    
    
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		Map<Character, Integer> map1 = new HashMap<Character, Integer>();
		for(int i=0;i<s.length();i++){
    
    
			
			char c = s.charAt(i);
			if(map1.get(c) == null){
    
    
				map1.put(c, 1);
			}else{
    
    
				map1.put(c, map1.get(c)+1);
			}
		}
		
		System.out.println(map1);
	}

}