Thread: FALSE & TRUE undeclared???

Why it says TRUE and FALSE are undeclared?? How to declare?? What I'm doing wrong?

Code:

#define s 256
main()
{
    char answer, t[s];
    char stop;

    stop = FALSE;
    while (stop = FALSE)
    {
        printf("Enter: ");
        gets(t);
        while (answer != 'Y'||answer != 'N')
        {
            printf("Continue?");
            answer = getchar();
        }
        if (answer = 'N')
        {
            stop = TRUE;
        }
    }
    system("PAUSE");

18 `FALSE' undeclared (first use in this function)
33 `TRUE' undeclared (first use in this function)

Other nits:

Code:

while (stop = FALSE)
...
if (answer = 'N')

Be aware there is a difference between = (assignment) and == (equality test).

---

Code:

char answer, t[s];
...
answer = getchar();

Note that getchar returns an int but in this case it does not look too critical that it be so. In other cases it does become important to use the proper type and as such you should get into the habit.

---

Code:

gets(t);

Avoid gets as it is susceptible to buffer overruns, prefer to use the fgets function instead which has protections against this.

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Code:

main()

You should explicitly state main as returning an int and do so at the end of the function.