程式碼如下，請參考/*creat by chiliu *2017-8-2 */#include<stdio.h>#include<string.h>int main(int argc,char *argv[])//主函式{ char ch; ch = getchar(); if ( ("a" <= ch && "z" >= ch) || ( "A" <= ch && "Z" >= ch) ) { printf("這是一個字母\n"); } else if("0"<=ch && "9">=ch) { printf("這是一個數字\n"); } else if(" " == ch) { printf("這是一個空格\n"); } return 0;}