C语言学习（一）ctype.h字符测试函数

 1     while (
 2            (ch = getchar())
 3            != ‘\n‘) {
 4         if (!isalpha(ch)) {
 5             putchar(ch);
 6         } else {
 7             putchar(ch + 1);
 8         }
 9     }
10     while ((ch = getchar()) != ‘\n‘) {
11         ch = tolower(ch);
12         putchar(ch);
13     }
14     putchar(ch);