C warning implicit declaration of function 'exit'

exit() is a library function, the respecive prototypes are present in the stdlib.h header file, inoder to call the process to specified code for exit function, you need to attach the as #include stdlib.h header in your program. that is the reason we should add the stdlib.h header. eventhough you can run the program, but it shows the warning message like below:

warning: incompatible implicit declaration of built-in function ‘exit’ [enabled by default]      

but, this kind of program not recommended, we need to take care of what we are given in the program,be cautious. warning may leads runtime error.

Do you have this preprocessor? If not, add it.

#include <stdlib.h>

Add:

#include <stdlib.h>

to the top of your program.