Declaring an array of classes...

This is a discussion on Declaring an array of classes... within the C++ Programming forums, part of the General Programming Boards category; It seems that these bits of code don't work: Code: CP wPawn('W')[8]; //expected a semi-colon CP wPawn[8]('W'); //bad array initializer ...

  1. #1
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    Question Declaring an array of classes...

    It seems that these bits of code don't work:
    Code:
        CP wPawn('W')[8]; //expected a semi-colon
    
        CP wPawn[8]('W'); //bad array initializer
    The class:
    Code:
    class CP
        {
           public:
                  CP(char color);             
                  ~CP();
                  bool isWhite();
           private:
                   char symbol;
                   bool white;     
           friend class square;
        };
    Should I just create a default constructor and declare the color for each individual object through a member function? Apparantly its impossible to define an array like that... If Anyone could tell me why, I would like to know.

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    an array of classes is just like an array of ints, ie: int myInts[8];
    that creates 8 ints, each seperate from the other. to access or set the value they contain you must do something like: myInts[2] = 3;

    try and apply this to your situation

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    You cannot specify a constructor argument when declaring an array of class objects unless you use an array initializer and initialize each one individually. You should use a vector, which is usually a better option than an array anyway. IMO it is definitely better than adding a default constructor when the class design doesn't call for one.
    Last edited by Daved; 10-26-2006 at 06:31 PM. Reason: Correction from Prelude

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    nadroj: yes, I know how to do that, read the whole topic before you post, not just the title. Thanks anyway.

    Daved: Ok, I've never used vecotrs before, but I'll look it up, thanks.

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    yes, I know how to do that, read the whole topic before you post, not just the title. Thanks anyway.
    i did read the whole thread so dont assume i didnt, thanks.

    what you want to do is create an array of 8 objects of [whatever] type and call the constructor for each at the same time, correct?

  6. #6
    Code Goddess Prelude's Avatar
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    >You cannot specify a constructor argument when declaring an array of class objects.
    Array initializer?
    My best code is written with the delete key.

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    You cannot specify a constructor argument when declaring an array of class objects unless you use an array initializer.

    But look up vector anyway, it is a good option.

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    Solution:
    Code:
    vector <CP> wPawn('W'); //
    This declares a vector (essentially a resizeable array) of the CP class using a constructor with parameters. It seems to dodge the previous syntax errors associated the normal array. However, I did have to declare an empty CP default constructor for it to work. Thanks, Daved.

  9. #9
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    To make a vector of size 8 all initialized with 'W' you would use this syntax:
    Code:
    vector <CP> wPawn(8, 'W');

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    Ooooooh, I wish I looked at that yesterday...

  11. #11
    Reverse Engineer maxorator's Avatar
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    Quote Originally Posted by Daved
    You cannot specify a constructor argument when declaring an array of class objects unless you use an array initializer and initialize each one individually. You should use a vector, which is usually a better option than an array anyway. IMO it is definitely better than adding a default constructor when the class design doesn't call for one.
    Isn't constructor called automatically?
    "The Internet treats censorship as damage and routes around it." - John Gilmore

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    It is. What's your point?
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
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