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);
}
}