String类使用举例

package Gaojiyuyan;
import java.util.Scanner;

public class StringleiUse {
    public static void main(String[] args) {
        
        
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入一个字符串：");
        String input=sc.next();
        int countUpper=0;
        int countLower=0;
        int countNumber=0;
        int countOther=0;
        char[] charArray=input.toCharArray();
        for (int i = 0; i < charArray.length; i++) {
            char ch=charArray[i];//当前字符
            if('A'<=ch&&ch<='Z'){
                countUpper++;
            } else if ('a' <= ch && ch <= 'Z') {

                countLower++;
            } else if ('0' <= ch && ch <= '9') {

                countNumber++;
            } else countOther++;
            }
        System.out.println("大写字母："+  countUpper);
        System.out.println("小写字母："+  countLower);
        System.out.println("数字："+  countNumber);
        System.out.println("其他："+  countOther);
        }

    }