编程实现：任意输入一个字符串，统计字符串中的数字个数和 字母个数

Python实现：

string = input("请输入一个字符串：")
letter_count = 0
digit_count = 0
for i in string:
    if i.isalpha():
        letter_count += 1
    elif i.isdigit():
        digit_count += 1
print("字母个数为：", letter_count)
print("数字个数为：", digit_count)

Java实现：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String string = scanner.nextLine();
        int letterCount = 0;
        int digitCount = 0;
        for (int i = 0; i < string.length(); i++) {
            if (Character.isLetter(string.charAt(i))) {
                letterCount++;
            } else if (Character.isDigit(string.charAt(i))) {
                digitCount++;
            }
        }
        System.out.println("字母个数为：" + letterCount);
        System.out.println("数字个数为：" + digitCount);
    }
}

C++实现：

#include <iostream>
using namespace std;

int main() {
    string s;
    cout << "请输入一个字符串：";
    getline(cin, s);
    int letterCount = 0;
    int digitCount = 0;
    for (int i = 0; i < s.length(); i++) {
        if (isalpha(s[i])) {
            letterCount++;
        } else if (isdigit(s[i])) {
            digitCount++;
        }
    }
    cout << "字母个数为：" << letterCount << endl;
    cout << "数字个数为：" << digitCount << endl;
    return 0;
}