program3_05.c

C语言入门经典一书的所有代码。书上面的所有代码均在此。希望大家喜欢

/* Program 3.5   Testing letters the easy way */
#include <stdio.h>
#include <ctype.h>
int main(void)
{
  char letter =0;                         /* Stores an input character */

  printf("Enter an upper case letter:");  /* Prompt for input          */
  scanf(" %c", &letter);                  /* Read the input character  */

  if ((letter >= 'A') && (letter <= 'Z')) /* Verify uppercase letter  */
  {
    letter += 'a'-'A';                    /* Convert to lowercase     */
    printf("You entered an uppercase %c.\n", letter);
  }
  else
    printf("You did not enter an uppercase letter.\n");
  return 0;
}