Question

A static variable inside a function is only allocated once during the lifetime of the program.

So if I have a function like:

void f(int n) {

  static int *a = new int[n];

}

and I first call

f(1)

and then

f(3)

how big will the array a be after the second call?

Answer 1

static local variables will be initialized when the control flow reaches the declaration for the first time. In this case, since the first time you used 1 as the n parameter, you’ll be allocating size for one int.

Doing this kind of stuff is a bad idea. You should just use a local, non-static, std::vector or some other higher level container.