题解 | #判断各类型字符个数#

方法一：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int numbers = 0;
        int words = 0;
        int space = 0;
        int other = 0;
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();

        for(int i=str.length()-1; i>=0; i--){
            char c = str.charAt(i);
            if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')){
                words++;
            }else if (c >= '0' && c <= '9'){
                numbers++;
            }else if (c == ' '){
                space++;
            }else{
                other++;
            }                
        }
            

        System.out.println("英文字母"+words+"数字"+numbers+"空格"+space+"其他"+other);
    }
}

方法二,API工程师：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int numbers = 0;
        int words = 0;
        int space = 0;
        int other = 0;
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();

        for(int i=str.length()-1; i>=0; i--){
            char c = str.charAt(i);
            if(Character.isLetter(c)){
                words++;
            }else if (Character.isDigit(c)){
                numbers++;
            }else if (Character.isWhitespace(c)){
                space++;
            }else{
                other++;
            }                
        }
            

        System.out.println("英文字母"+words+"数字"+numbers+"空格"+space+"其他"+other);
    }
}