Question

i tried to look up whether virtual function determine during compilation or while running.
while looking i found something as dynamic linking/late binding
but i didn’t understand if it means that the function itself determine during compilation before the executable or during the executable.

can someone please explain?

Answer 1

For virtual functions resolution is done at runtime. When you have an instance of an object the resolution of which method to call is known only when the program is running because only at runtime you know the exact type of this instance. For non-virtual functions this resolution can be done at compile time because it is known that only this method can be called and there cannot be child classes overriding it. Also that’s why virtual method calls are a bit slower (absolutely negligibly but slower than non-virtual method calls). This article explains the concept in more details.