[EOF Problem] Extra Character In Output

This is a discussion on [EOF Problem] Extra Character In Output within the C++ Programming forums, part of the General Programming Boards category; I'm reading characters out of a text file and printing them to the console via this code: Code: ifstream textFile; ...

  1. #1
    Young C n00b
    Join Date
    Jul 2006
    Posts
    59

    [EOF Problem] Extra Character In Output

    I'm reading characters out of a text file and printing them to the console via this code:
    Code:
    ifstream textFile;
    textFile.open(s.c_str(), ios::in);
    
    char c = NULL;
    while(!textFile.eof()) {
    	textFile >> c;
    	cout << c;
    }
    Here is what is actually in the text file:
    1234567890

    This is what gets printed:
    12345678900


    Why does it print the last character twice? What can I do to avoid it?

  2. #2
    C++ Witch laserlight's Avatar
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    Singapore
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    Read the FAQ on why you should not use eof() to control a loop like that (in fact, your observation is the answer why). Rather, use the result of textFile >> c.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

  3. #3
    Sweet
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    Tucson, Arizona
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    Using eof is not a good way to control a file read loop. Just use operator >>
    Code:
    while(textFile>>c){
       cout<<c;
    }
    Woop?

  4. #4
    Young C n00b
    Join Date
    Jul 2006
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    59
    Awesome answers. Thank you both for your help.

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