Some questions about pointers

This is a discussion on Some questions about pointers within the C++ Programming forums, part of the General Programming Boards category; here is my basic Idea of pointers from what I learned so far. Plz tell me if I am correct ...

  1. #1
    Ethernal Noob
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    Some questions about pointers

    here is my basic Idea of pointers from what I learned so far. Plz tell me if I am correct and the second part with the pCat is a little confusing.
    Code:
    int * pPoint = 5;    // this deferences a pointer, assigning it 5.
    cout << &pPoint;  // shows the address of the pointer
    
    //some other q's
    int cat=5;
    *pCat = &myAge;
    cout << *pCat;  //now does this return the address of the cat,
                              //or the value 5 which is stored in the address?
    
    //also
    cout << pCat;  // what would that output?
    Last edited by indigo0086; 09-08-2002 at 10:51 AM.

  2. #2
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    Toss it in a complier and find out. Not trying to be rude, but you will find out that when beginning C++ you will do this often. I use VC++ and used to open 2 versions of the program, 1 for the project I was working on, and 1 to test stuff out. I also put cout statments all over the place so I can check values as they run through the program. This is just one way to look for bugs. Good Luck!
    This space for Rent.

  3. #3
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    yeh, I see the output, but I don't see why that is the output.

  4. #4
    Registered User Dr. Bebop's Avatar
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    None of it should work, you can't assign a constant value to a pointer, so

    int * pPoint = 5;

    is wrong. You need to make another variable to hold the 5 and then have the pointer point to the address of that variable.

    int p = 5;
    int * pPoint = &p;

    You need to declare variables before using them, so

    *pCat = &myAge;

    is also wrong. Both pCat and myAge don't exist in the code you posted. Assuming that they both did exist,

    cout << *pCat;

    would print whatever value is in myAge because that is where pCat points to. You dereference the pointer which means "go to the address pointed to and return the contents of it". And

    cout << pCat;

    would print whatever address myAge is located at because cout prints the contents of the variable you pass it, a pointer is a variable that holds an address, so the output would be an address.

    Bebop
    Processing error: Stupidity detected.
    ------------------------------
    Dr. Bebop
    Windows XP Professional Ed.
    Microsoft Visual Studio 6

  5. #5
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    yeah, sorry I didn't declare them, but I was just using them to assume they were. Thanks, I get it now, so if I just wanted to show the address I woud not use (*). If I wanted to get the value at the address I would use the (*) I understand it now.

  6. #6
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    Sorry, I didn't fully understand what you were asking.
    This space for Rent.

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