Loop Query

This is a discussion on Loop Query within the C# Programming forums, part of the General Programming Boards category; Hey, Im having a problem with the below code: Code: AddressBook addr = new AddressBook(); do { menu_choice = addr.DisplayMenu(); ...

  1. #1
    Registered User (TNT)'s Avatar
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    Loop Query

    Hey,

    Im having a problem with the below code:

    Code:
                AddressBook addr = new AddressBook();
    
                do
                {
                    
                    menu_choice = addr.DisplayMenu();
                 ....
                 } while (cont_menu != false);
    In that code menu_choice (int) is always the same value as is set in the first time of the loop, as if the DisplayMenu() method is never called after the 1st iteration.

    However if i place AddressBook addr = new AddressBook(); inside the loop it works and displays the menu and sets the correct value of menu_choice.

    This to me didnt seem the correct way of doing it though, Becase surly creating a new object/instance to a class for every iteration of the loop is inefficent?

    Please can someone explain how this should be done.

    Thanks
    TNT
    You Can Stop Me, But You Cant Stop Us All

  2. #2
    the hat of redundancy hat nvoigt's Avatar
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    What is an AddressBook and what does DisplayMenu do ? Google didn't find anything and I don't remember such a class.
    hth
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  3. #3
    Registered User (TNT)'s Avatar
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    Sorry i should have said, its a custom class i made, DisplayMenu() method displays a simple menu for the address book e.g add new address. The menu is shown again at the top of the loop when the requested option has been chosen and completed from the menu. I use a switch statement in the loop to flick through menu_choice and perform the desired operation.

    I have attached the full code if it helps. Im new to C#, and im just questioning if its correct or not to create a new object to the addressbook class inside every iteration of the loop.
    Attached Files Attached Files
    Last edited by (TNT); 02-12-2006 at 07:29 AM.
    TNT
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  4. #4
    Guest Sebastiani's Avatar
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    >> while (gotchoice == false)

    you need to reinitialize the variable at the beginning of the function. in general, whenever you have an object behave as it did in your example, one of the class members is in an indeterminate state.
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

  5. #5
    Registered User (TNT)'s Avatar
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    Thanks for that it fixed the problem, I was under the impression the function would need to be static to retain its value and need reinitializing like that.
    TNT
    You Can Stop Me, But You Cant Stop Us All

  6. #6
    Registered User mrafcho001's Avatar
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    Im new to C#, but I was reading somewhere that is bad practice to compare ints to bools.

    If if cont_menu is only going to be used to determine if it should quit out of the loop, then change it to bool.
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