Thread: Check if string is null

Hi,

Can you tell me how to check if a string is null in C?

I tried p != '\0' doent seem to wrk though!

thanks

Do you want to test if a character array points to NULL or a string is empty? Your wording doesn't make much sense.

But the two I said:

Code:

p == NULL /* True if character array points to NULL */
!*p or *p == '\0' /* True if string empty */

Code:

char *p=NULL;
if (!p) printf("p is null");
else printf("p is not null");

keep in mind that if i didn't write the assignment (p=NULL) its value would be undefined and the if statement wouldn't work. in a string '\0' is the terminating null byte, you can check when a string is finished but you need to dereference the address:

Code:

char *p;
if (*p=='\0')...

Hope that helped