1. C++
```cpp
include using namespace std; int main() { char a; int x = 0; // 正序打印字母表 for (a = 'a'; a = 'a' - 1; a--) { cout << a; x++; if (x == 13) { cout << endl; x = 0; } } return 0; } ``` 2. Python ```python for i in range(26): print(chr(i + ord('a')), end=' ') print() for i in range(26): print(chr(i + ord('A')), end=' ') print() ``` 3. Java ```java public class AlphabetDemo { public static void main(String[] args) { for (char c = 'a'; c <= 'z'; c++) { System.out.println("value: " + (int) c + " char: " + c); } for (char c = 'A'; c <= 'Z'; c++) { System.out.println("value: " + (int) c + " char: " + c); } } } ``` 4. JavaScript ```javascript for (let i = 0; i < 26; i++) { console.log(`value: ${i + 97} char: ${String.fromCharCode(i + 97)}`); } for (let i = 0; i < 26; i++) { console.log(`value: ${i + 65} char: ${String.fromCharCode(i + 65)}`); } ``` 5. C ```csharp using System; class Program { static void Main() { for (char c = 'a'; c <= 'z'; c++) { Console.WriteLine($"value: {c} char: {c}"); } for (char c = 'A'; c <= 'Z'; c++) { Console.WriteLine($"value: {c} char: {c}"); } } } ``` 6. Ruby ```ruby for i in 0..25 puts "value: {i + 97} char: {i + 97}" end for i in 0..25 puts "value: {i + 65} char: {i + 65}" end ``` 这些示例展示了如何在不同的编程语言中打印字母表。你可以根据自己的需求和使用的编程语言选择合适的方法。