Logical Operator not working?

This is a discussion on Logical Operator not working? within the C++ Programming forums, part of the General Programming Boards category; For some reason, the below code will not work (ie, the loop will not break out if either a 'Q' ...

  1. #1
    Registered User
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    Sep 2004
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    Post Logical Operator not working?

    For some reason, the below code will not work (ie, the loop will not break out if either a 'Q' or 'q' is entered for line).

    Code:
    numelms = 81;
    char line[numelms];
    
    while (*line != 'Q' || * line != 'q')
    {
    cin.getline(line, numelms);
    }
    Help!

  2. #2
    Registered User manofsteel972's Avatar
    Join Date
    Mar 2004
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    317
    [edit]
    oops nevermind
    [/edit]

    nevermind just change it to and
    try
    change to &&
    Code:
    while(*line!='Q'&& *line !='q')
    [explanation]

    the test you have states that
    it will be true if either
    *line!='Q'
    OR
    *line!='q'

    problem is that when you enter a Q or q one is true and the other is false
    1 OR 0 =1; so it alwasy evaluates to be true;

    if you change it to AND 1 AND 0 is 0 and the loop exits;
    [/explanation]
    Last edited by manofsteel972; 09-27-2004 at 06:22 AM.
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  3. #3
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    Man, I can't believe I didn't see that... I did this kind of loop all the time and Java... it's too early to be programming man.

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