classes

This is a discussion on classes within the C++ Programming forums, part of the General Programming Boards category; ok, i know im asking a lot, but would anyone be able to explain how functions work, an example would ...

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    classes

    ok, i know im asking a lot, but would anyone be able to explain how functions work, an example would be great, or atleast a good tutorial, i've read the one on this site atleast 6 times thanks
    -edit: in fact im reading it right now

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    Registered User Boomba's Avatar
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    you wanna know how functions or classes work or both?

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    well i understand functions, just classes confuse the hell out of me

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    Try this for functions, and this for classes.
    Also, if you know C I used this site to understand C++ better.
    Everything is relative...

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    thanks, now would you recomend i read the functions one first, even though i have a good grip on them? or should i go straight to classes?

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    I'm probably not the best person to ask. I just started on C++. But from what I know I would look over the functions, that is used to wrtite the methods for your classes. I think you should understand how functions work fairly well though.

    Good luck.
    Everything is relative...

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    Advanced Novice linucksrox's Avatar
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    definitely functions first. because, well, what's a class without functions? well, just a structure. (don't worry about structures, if you learn classes you'll understand structures).
    "What are all you parallelograms doing here?" - Peter Griffin (to Joe and his wheelchair buddies)

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    ok, thanks

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    in all of the examples on the funtion page they use the header
    fstream.h.... what is this? why dont they use iostream?

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    Registered User Tonto's Avatar
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    Code:
    #include <fstream>
    ANSI C++ Headers have no .h extension. Read: http://www.cplusplus.com/doc/ansi/hfiles.html for more info. fstream in particular contains a file I/O class which inherits from the standard console iostream classes (used in plain console I/O). I/O stands for input/output.

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    i know they dont have any .h headers, but this uses the header fstream.h and im sure it will work the same if it was just fstream, i was just wondering why they use fstream instead of iostream
    Last edited by sreetvert83; 08-28-2005 at 10:04 AM.

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    Because iostream has different functions built in from fstream. Iostream contains things such as cout and cin, whearas fstream is for file I/O.

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    so, i should only use fstream if i want to do file i/o otherwise just use iostream right?

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    <ChrisFarley>That's correct!</ChrisFarley>

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    Uh, you can use more than one header file. Use iostream if you use cin or cout anywhere, and use fstream if you're using file I/O. Example:

    Code:
    #include <iostream>
    #include <fstream>
    #include <string> //Stuff related to the datatype "string"
    
    using namespace std;
    
    int main() {
         string a;
    
         a = something;
         cout << a; //Iostream is needed for cout to work.
         ofstream b("example.txt") //Fstream is needed for this to work.
         b << a: //I know fstream is probably needed for this, but I'm not sure if iostream is, since you don't have "cout" involved...
                     //Then again, there is the << operator, so I'd say both headers are needed here.
    }
    Yes, I am very unsure about things sometimes. :P Suffice to say that if you use fstream, you'll probably want iostream.
    Last edited by linkofazeroth; 08-28-2005 at 11:05 AM.

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