isalphaプロジェクト - bg1wiki @ ウィキ

isalpha.c

#include <stdio.h>
#include <ctype.h>
 
int main(void){
 
  int c;
 
  c = getchar();
 
  if (isalpha(c)){
 
    printf("%c is alphabet.\n", (char)c);
 
  }
 
  return 0;
 
}