time() function

Question

Why is its operand 0 ? Can it have any other operand?

Answer 1

see here: http://www.cplusplus.com/reference/ctime/

Basically it has two functions. The first is to return the current system time.

The second is it can give this returned time to an object of type time_t

such as
time_t myTimer;
time(&myTimer);

We use 0 to tell it not to assign the time anywhere but just return it.

Answer 2

Like jay explained, this 0 is here simply to make the time function return to nothing...
Basically 0 represents NULL here, to make the function pass the value to a null pointer which has no memory...

Answer 3

Thanks!