dynamic allocation of structs can somebody help me get this thing straight...,

am making a dynamic struct.., something is wrong here..,

Code:

---


typedef struct tagASTRUCT
{
    int m_data;
    void Create(int data)
    {
      m_data = data;
    }
        {
        }
}*ASTRUCT

ASTRUCT object;

// now, i'd like to specify the number of structs that i'll be usingo n runtime..,

object = new tagASTRUCT[10]; // example 10 kinds of this,

---

so how do i access the function in it? like this?

object.Create(...);
why is not like this?
object->Create(...);

thanks,

okey, probably it'll be better if you could give me a sample how to specify the size and at the same time use it on runtime?

thanks a lot! :)

This would be a bit easier to follow and more useful if you choose to create a regular instance of the struct.

Code:

---

typedef struct tagASTRUCT
{
  int m_data;
  void Create(int data)
  {
    m_data = data;
  }
} ASTRUCT;

ASTRUCT *object;

---

>object = new tagASTRUCT[10];
In an array you determine the element and access the item with the dot operator. You can use the -> operator, but only on the first element.

Code:

---

#include <iostream>

typedef struct tagASTRUCT
{
  int m_data;
  void Create(int data)
  {
    m_data = data;
  }
} ASTRUCT;

ASTRUCT *object;

int main ( void )
{
  object = new tagASTRUCT[2];
  object->Create(10);
  object[1].Create(20);
  std::cout<< object->m_data <<"\n";
  std::cout<< object[1].m_data <<"\n";
  return 0;
}

---

Try changing those access methods around and see what errors you get.

>give me a sample how to specify the size and at the same time use it on runtime?
Use a variable.

Code:

---

cout<<"Enter the number of records: ";
cin>>size;
object = new tagASTRUCT[size];

---

-Prelude

hiya prelude, thanks for the very fast response whew i've been strugling abou this for an hour already... anyway hope ye don't mind got some more questions...,

>object = new tagASTRUCT[10];

err., you could also use ASTRUCT right? or no? plz explain if no..,

>ASTRUCT *object;

but um., why is it not possible to put that with the struct just like i did? then declare like this,

ASTRUCT object; // this is also the same as ASTRUCT * object right?

and why did you say it will be more useful?
>In an array you determine the element and access the item with the dot operator. You can use the -> operator, but only on the first element. <

yeah, this thing got me confused, i kept on wondering how come the arrow operator doesn't want to work(using VC)? but why is it like that? can you explain plz?

thanks a lot prelude!!! :)

hi one more thing, about memcpy,

is this right? i'd like to copy all the contents of object(10 of this)

memcpy(buffer, object, sizeof(object));

where buffer is declared as void *;


thanks again, :)

I might be way of on this but I will blur it out anyway. My C compiler usally flags 'new' as non C and forces me to use malloc instead. Am I correct if I claim that new is C++ and not C?

yeah, when you're in C++, you use the new, and in c, malloc, :)

Ops my bad. For some reason I read this post as posted on the C board. sorry