question about pointers

This is a discussion on question about pointers within the C++ Programming forums, part of the General Programming Boards category; when declaring: Code: Account nAcnt1; and Code: Account *nAcnt2; the latter is a pointer to Account class. but if we ...

  1. #1
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    question about pointers

    when declaring:
    Code:
    Account nAcnt1;
    and

    Code:
    Account *nAcnt2;
    the latter is a pointer to Account class.

    but if we go:

    Code:
    nAcnt2=new Account;
    what do u call this new type?

  2. #2
    ... arjunajay's Avatar
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    We call it
    "A pointer pointing to a dynamicaly allocated object of an 'Account' class."
    Yes I'm trying to confuse you.

  3. #3
    aoeuhtns
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    Quote Originally Posted by hoangvo
    when declaring:
    Code:
    Account nAcnt1;
    and

    Code:
    Account *nAcnt2;
    the latter is a pointer to Account class.
    Nope, the latter is a pointer to an Account object. None exists at the (uninitialized) location it's pointing at.

    Quote Originally Posted by hoangvo
    but if we go:

    Code:
    nAcnt2=new Account;
    what do u call this new type?
    nAcnt2 is still a pointer to an Account object. Its type won't change. This time an Account object exists at the location it's pointing at.

  4. #4
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    Pointers are variables that store addresses. With this statement:

    Account *nAcnt2;

    you create a pointer variable called nAcnt2, which you have declared will store the address of an Account object. I prefer to use this format:

    Account* nAcnt2;

    That format makes it clear the variable name is 'nAcnt2', and the type is Account*.

    The 'new' keyword dynamically creates an object and returns its address in memory. So, here:

    nAcnt2=new Account;

    you create an Account object, and assign its address to the variable nAcnt2.
    Last edited by 7stud; 07-24-2005 at 12:19 PM.

  5. #5
    Frequently Quite Prolix dwks's Avatar
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    Code:
    Account a;
    Account *p = &a;
    Declares a pointer to a. You can access a as a or *p.

    Code:
    Account *p = new Account;
    Declares a pointer to a newly allocated Account. But in this case, the only way you can access this Account is through *p.
    dwk

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