输入一个字符串 判断到底有几个大写字母 小写字母 以及数字

1.这里我们用到了charAt()属性，先返回所有的字符串，逐个进行统计

import java.util.Scanner;public class login {public static void main(String[] args) {Scanner sc = new Scanner(System.in);System.out.println("请输入一个字符串");String line = sc.nextLine();int Bigcount=0;int shuzi=0;int smallcount=0;for (int i=0;i<line.length();i++){char ch=line.charAt(i);if (ch>='A'&&ch<='Z'){Bigcount++;}if (ch>='0'&&ch<='9'){shuzi++;}if (ch>='a'&&ch<='z'){smallcount++;}}System.out.println("大写字母有"+Bigcount+"个");System.out.println("小写字母有"+smallcount+"个");System.out.println("数字有"+shuzi+"个");}}