Thread: How do I use strings with if statements? (COMPARISON)

  1. #1
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    How do I use strings with if statements? (COMPARISON)

    Hi
    I'm using something like this to give the user a way of choosing what effects to use in an audio processing console applictaion.

    Code:
     int Q;
        cout << "Do you want to add effect?\n" << "1 for Yes or 0 for No." << endl;
        cin >> Q;
        if (Q == 1)
        {
           // EFFECT FUNCTION GOES HERE
        }
        else if (Q == 0)
          //  MOVES ONTO NEXT FUNCTION

    how could I do this with strings? so the user would put "yes" or "no"? I have looked up sting.compare but I don't know how to apply it. I tried something like this.

    Code:
     string Q1("yes");
        string Q2("no");
        string Q3;
        cout << "Do you want to add effect?\n" << "yes or no" << endl;
        cin >> Q3;
        if (Q3.compare(Q1));
        {
            // EFFECT FUNCTION GOES HERE
        }
        if (Q3.compare(Q2));
            // MOVES ONTO NEXT FUNCTION
    

    but it doesn't work (I type in "no" and it still runs the effect)



    THANK YOU

  2. #2
    and the hat of int overfl Salem's Avatar
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    > if (Q3.compare(Q1));
    Two things.
    1. The ; at the end makes it a useless comparison.
    2. string::compare - C++ Reference returns 0 when the strings are equal.

    So you would need to do
    if ( Q3.compare(Q1) == 0 )
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.

  3. #3
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    cheers my G <3

  4. #4
    C++ Witch laserlight's Avatar
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    Why not just write:
    Code:
    if (Q3 == Q1)
    ?
    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

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