What is the meaning of void sum void? And why is void used 2 times?

Question

its is in the chapter functions. and plz explain me with an example. plz

Answer 1

void sum(void);
The first void tells that the function sum doesn't return anything.
The second void means that the function sum doesn't accept anything as a parameter.
It is equivalent to writing void sum();

Answer 2

ookay. Thaaaaank you very much.