C经典之13-Asking的实时监听---ShinePans

#include <stdio.h>#include <conio.h>#include <stdlib.h>  //system(); 这个指令需要用到此头文件#include <ctype.h> //toupper要用到#include <malloc.h> //在内存管理时用到的头文件void main(){char letter;  // Letter typed by the userprintf("Do you want to continue? (Y/N): ");letter = _getch();          // Get the letter  letter = toupper(letter);  // Convert letter to uppercasewhile ((letter != 'Y') && (letter != 'N')){_putch(7);                  // Beep the speakerletter = _getch();          // Get the letter  letter = toupper(letter);  // Convert letter to uppercase}printf("\nYour response was %c\n", letter);system("pause");}