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

[Glen V. <gve...@pa...>]

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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