Thread: inheritance and polymorphism uses...

  1. #1
    tetra
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    inheritance and polymorphism uses...

    this is probably the most rediculous question i probably will ever ask..


    what are actual uses of polymorphism and inheritance..

  2. #2
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    variant data types?

    http://cboard.cprogramming.com/showt...threadid=39087

    download that file. comment out most of the code in main, then uncomment the huge chunk.

    You can even check uninitialized data.

  3. #3
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    Anytime you need a switch statement based on the type of the object pointed to by the base class pointer.

  4. #4
    Confused Magos's Avatar
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    I have an example of inheritance. I'm working on a game, and in it there are several different objects (items, enemies, bullets, special effects etc...). Most of these use the same kind of data, like all of them have a position, a dimension, a direction etc... Instead of rewriting the same stuff over and over for each type, I made a base class containing that data. Then all of my game objects inherited from that base class, and made som add-ons specific for that type.
    It saves time and space.

    As for polymorphsm, I have no good example. Basically it lets you use the same names for different arguments.
    So instead of typing:
    Code:
    int AddInt(int X, int Y);
    float AddFloat(float X, float Y);
    double AddDouble(double X, double Y);
    You type:
    Code:
    int Add(int X, int Y);
    float Add(float X, float Y);
    double Add(double X, double Y);
    Voila! Using the same name, it's easier to remember them (duh!) and can make the coding easier... maybe...
    MagosX.com

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  5. #5
    Magically delicious LuckY's Avatar
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    Polymorphism allows you to write a function that handles different specified data types in the same intended way. Think about the "cout" object... It allows you to do something like this:
    cout << (int)iVal << (double)dVal << (char)ch << (const char*)str;
    The reason you can do that is polymorphism... Without it, you would have to do something like this:
    cout.printInt(iVal);
    cout.printDouble(dVal);
    cout.printChar(ch);
    cout.printString(str);

    Inheritance is a very important part of C++. With it you can create new classes based on existing class without having to recode tons of tried and true code.. Think about if you want to create a specialized button in a gui app. If you had to somehow code a class from scratch that does everything that a button does just so you can add some new functionality, the computer programmer suicide rate would sky-rocket... Instead, you can create a new button class derived from CButton and add the functionality you want to it...

    Make sense?
    Last edited by LuckY; 05-06-2003 at 01:54 PM.

  6. #6
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    Look up templates, too. They're even more useful... except my compiler (VC++6.0) has a ton of template related bugs in their code.

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