W3School TIY Editor

#include <stdio.h> #include <stdlib.h> #include <ctype.h> int main() { char c = '\n'; if (iscntrl(c)) { printf("'%c' (ASCII 值 %d) 是控制字符", c, c); } else { printf("'%c' (ASCII 值 %d) 不是控制字符", c, c); } return 0; }