โปรแกรม C ตรวจสอบคำสงวน (Keyword)

ตรวจสอบว่าสตริงที่ให้มาเป็น Keyword ของ C/C++ หรือไม่ โดยเปรียบเทียบกับรายการ 32 คำสงวนของ C และ 30 คำเพิ่มของ C++

Keywords ของ C (32 คำ)

auto, break, case, char, const, continue, default, do,
double, else, enum, extern, float, for, goto, if,
int, long, register, return, short, signed, sizeof, static,
struct, switch, typedef, union, unsigned, void, volatile, while

โค้ดตัวอย่าง

#include <stdio.h>
#include <string.h>

int main() {
    char *kw[] = {"auto","break","case","char","const","continue","default","do",
                  "double","else","enum","extern","float","for","goto","if",
                  "int","long","register","return","short","signed","sizeof","static",
                  "struct","switch","typedef","union","unsigned","void","volatile","while"};
    char str[] = "for";
    int found = 0;
    for (int i = 0; i < 32; i++)
        if (strcmp(str, kw[i]) == 0) { found = 1; break; }
    printf("%s is %sa keyword\n", str, found ? "" : "not ");
    return 0;
}

ผลลัพธ์

for is a keyword