java 入门 charAt

package com.demo2;import java.util.Scanner;/*** 统计数量* 数字* 大写字母* 小写字母*/
public class charAtDemo2 {protected static int azsum = 0;protected static int AZsum = 0;protected static int numsum = 0;public static void main(String[] args) {System.out.println("请输入字符串");Scanner sc = new Scanner(System.in);String line = sc.nextLine();for (int i=0;i<line.length();i++){char ch = line.charAt(i); // 字符if(ch >= 'a' && ch<= 'z'){azsum++;}else if(ch  >= 'A' && ch <='Z'){AZsum++;}else if(ch >= '1'&& ch<='9'){numsum++;}}System.out.println("a-z:"+azsum);System.out.println("A-Z:"+AZsum);System.out.println("1-9:"+numsum);}
}