统计字符串中每个字符出现的个数

统计字符串中每个字符出现的个数

package com.bwf.cn.map;import java.util.HashMap;import java.util.Map;public class Test01_Map {/** * 统计字符串中每个字符出现的次数String str = "aaaabbbcccccccccc"; */public static void main(String[] args) {// TODO Auto-generated method stubString str = "aaaabbbcccccccccc";char[] arr = str.toCharArray();Map<Character, Integer> map = new HashMap<>();for (char c : arr) {//if(!map.containsKey(c)){//map.put(c, 1);//}else{//map.put(c, map.get(c)+1);//}map.put(c, map.containsKey(c) ? map.get(c)+1:1);}  for (Character key : map.keySet()) {System.out.println(key+" :  "+map.get(key));}}}