we cant define function before using it??

Question

ex; int main()
{ printsomething();}

void printsomething{
cout<<"hi hello";
}

if it is any eror helpme
plsss

but
how will answer correct
if i use void first
int last..

Answer 1

void printsomething();

int main
{
return 0;
}
void printsomething()
{
cout<<endl;
}

Answer 2

you must declare a "prototype" of the funtion before main so the compiler know that the funtion is defined after main.
void printsomething(); //prototype
int main(){}
void printsomething(){
//definition here
}

Answer 3

what is it???