Re: [Dev-C++] Stress with structs and pointers.

[David M. <ci...@ya...>]

You sure constructors will work in a C enviroment? That is
one pre-requisite that I am hating.

With respect to #2, I was asking how you would get to the
value pointed to by a pointer that is part of a struct.

--- Glen Vermeylen <gve...@pa...> wrote:
> 1) Structs also support constructors (see below for
> example program)
> 2) Don't know what you mean. But if you mean that it can
> take any type 
> of members: yes. If you want to get to that member, just
> do it the same 
> way: struct.membername. It's the same way for pointers or
> other variables.
> 3) *(struct.membername). It's very easy to test this
> yourself.
> 4) plain logic: you got a pointer to struct, so use
> struct->member. The 
> variable is a pointer, so dereference the endresult:
> *(struct->member).
> *((*struct).member) would be an alternative way
> (dereference your 
> pointer to struct, get its member, dereference that) :)
> 
> I wrote a little test to be sure (and in the process I
> learned stuff too 
> :) ). This incorporates everything you need to know:
> 
> #include <iostream>
> #include <cstdlib>
> using namespace std;
> 
> typedef struct test{
>     public:
>         int* a;
>         test();
> };
> 
> test::test(){
>     a = new(int);
>     *a = 5;
>     cout << "In constructor: " << *a << endl;
> }
> 
> int main(){
>     test *x = new test();
>     cout << "*(x->a): " << *(x->a) << endl;
>     cout << "*((*x).a): " << *((*x).a) << endl;
>     system("pause");
> }
> 
> David McKen wrote:
> 
> > Ok, I need some clarification on a couple topics
> invloving pointers 
> > and pointers.
> >  
> > 1) when a struct is created. All that can be assumed is
> that it 
> > contains trash right? What is a portable way to
> initalize everything 
> > to 0? mset?
> >  
> > 2) when a structure contains a pointer. Access to the
> address (not the 
> > value) comes in the form
> {struct_variable_name}.{member_name}?
> >  
> > 3) how do you de-refrence the pointer in #2 to get the
> value of the 
> > variable? {struct_variable_name}.*{member_name}?
> >  
> > 4) if you have a pointer to the structure you access
> the members via 
> > '->'. If a member of the structure is a pointer the
> address is gotten 
> > via {struct_varible_name}->{member_name}? If so how
> does one get the 
> > value of the varible?
> {struct_variable_name}->*{member_name}?
> >  
> > Thanks in Advance
> > David McKen
> >  
> > P.S. Was begining to run out of hair!
> >
>
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> 


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