follow up to if and then statements

This is a discussion on follow up to if and then statements within the C++ Programming forums, part of the General Programming Boards category; ok this is starting to get irrating. i have these as constansts: // constants for under 50,000 miles; const double ...

  1. #1
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    Join Date
    Sep 2001
    Posts
    4

    follow up to if and then statements

    ok this is starting to get irrating. i have these as constansts:

    // constants for under 50,000 miles;

    const double Carbon_Monoxide = 3.4;
    const double Hydro_Carbons = 0.31;
    const double Nitrogen_Oxides = 0.4;
    const double Nonmethane_HydroCarbons = 0.25;

    I also have these labeled as "1" , "2" , "3", and "4" (same order)

    one of my input varialbes is "pollutant" (can equal anthing 1 , 0.4
    etc. etc.

    my if and then statement looks like this:

    if(miles < 50000)
    dataOK = true;
    else
    dataOK = false;

    if (dataOK) // start of true value;

    if(number >= pollutant)
    {
    cout << "passed emissions " << endl;
    }
    else
    {

    cout << "emissions level exceeded " << endl;
    }


    The problem is this bug keeps telling me that if I enter number 2
    which would be "Hydro_Carbons = 0.31"
    and "pollutant" = 0.42

    it becomes true when it should be false... weird to me cause i'm a beginner and can't fix it :P << all numbers were set to doubles>> if that matters at all.

  2. #2
    Registered User
    Join Date
    Aug 2001
    Posts
    154

    Re: follow up to if and then statements

    Originally posted by mikezmr2
    ok this is starting to get irrating. i have these as constansts:

    // constants for under 50,000 miles;

    const double Carbon_Monoxide = 3.4;
    const double Hydro_Carbons = 0.31;
    const double Nitrogen_Oxides = 0.4;
    const double Nonmethane_HydroCarbons = 0.25;

    I also have these labeled as "1" , "2" , "3", and "4" (same order)

    one of my input varialbes is "pollutant" (can equal anthing 1 , 0.4
    etc. etc.

    my if and then statement looks like this:

    if(miles < 50000)
    dataOK = true;
    else
    dataOK = false;

    if (dataOK) // start of true value;

    if(number >= pollutant)
    {
    cout << "passed emissions " << endl;
    }
    else
    {

    cout << "emissions level exceeded " << endl;
    }


    The problem is this bug keeps telling me that if I enter number 2
    which would be "Hydro_Carbons = 0.31"
    and "pollutant" = 0.42

    it becomes true when it should be false... weird to me cause i'm a beginner and can't fix it :P << all numbers were set to doubles>> if that matters at all.
    Well, you could tighten the code up by:
    Code:
    dataOK = false;
    if (miles < 50000)
    {
       dataOK = true;
       if (number >= pollutant)
          cout << "Passed emissions";
       else
          cout << "Emission levels exceeded";
    }
    The problem might be where you assign number to the various pollutants. It may be checking if 2 is greater than or equal to 0.42, which of course it is. Assigning 2 to "Hydrocarbons = 0.31"? As written, you're assigning a string to a numeric variable. That specifically may not be the problem, but assigning the 2 might be. 2 is a literal constant, not a variable. You can't have
    double hydrocarbons = 0.31 and double 2 = hydrocarbons. Without seeing your code there, it's hard to say.

  3. #3
    Registered User
    Join Date
    Sep 2001
    Posts
    4
    yes, i think ur right, the program is reading as "number" to the actually number , ex 1,2,3,4. ok. heh damn something so simple couldn't even figure that out

    thanks for ur help.

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