Java程序来计算每个字符的出现次数

String myStr = "thisisit";

HashMap  hashMap = new HashMap<>(); for (int i = myStr.length() - 1; i >= 0; i--) { if (hashMap.containsKey(myStr.charAt(i))) { int count = hashMap.get(myStr.charAt(i)); hashMap.put(myStr.charAt(i), ++count); } else { hashMap.put(myStr.charAt(i),1); } }

import java.util.HashMap; public class Demo { public static void main(String[] args) { String myStr = "thisisit"; System.out.println("String ="+myStr); HashMap
         
          hashMap = new HashMap<>(); for (int i = myStr.length() - 1; i >= 0; i--) { if (hashMap.containsKey(myStr.charAt(i))) { int count = hashMap.get(myStr.charAt(i)); hashMap.put(myStr.charAt(i), ++count); } else { hashMap.put(myStr.charAt(i),1); } } System.out.println("Counting occurrences of each character = "+hashMap); } }
         

String =thisisit Counting occurrences of each character = {s=2, t=2, h=1, i=3}