C++ newbie needs help with simple conversion programming

This is a discussion on C++ newbie needs help with simple conversion programming within the C++ Programming forums, part of the General Programming Boards category; Hi, I'm trying to make a program that converts Fahrenheit into Celsius and Kelvin. #include <iostream> #include <cmath> #include <cstdlib> ...

  1. #1
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    C++ newbie needs help with simple conversion programming

    Hi, I'm trying to make a program that converts Fahrenheit into Celsius and Kelvin.

    #include <iostream>
    #include <cmath>
    #include <cstdlib>

    int main(int argc, char *argv[])
    {
    double fah, cel, kel;
    char ans;
    do
    {
    cout<<"Enter the temperature in Fahrenheit: "; // I get error here..."cout" undeclared
    cin>>fah;

    cel = (5.0 / 9.0) * (fah - 32.0);
    kel = (cel + 273.0);

    cout<<"The temperature is "<<cel<<" degree Celsius and "<<kel<<" Kelvin."<<endl;
    cout<<endl<<endl
    <<"Do you want to do this again? ";
    cin>>ans;
    fflush(stdin);
    }while(ans=='Y' || ans == 'y');
    system("PAUSE");
    return EXIT_SUCCESS;
    }
    Last edited by djayyyyy; 10-16-2010 at 11:43 PM.

  2. #2
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    You either need to add
    Code:
    using namespace std;
    before main() or use
    Code:
    std::cout<<"Enter the temperature in Fahrenheit: ";
    std::cin>>fah;
    and all other things in the std namespace.

    Jim

  3. #3
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    Also do not
    Code:
    fflush(stdin);
    Jim

  4. #4
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    And to quibble, zero degrees celcius is 273.15 kelvin
    Right 98% of the time, and don't care about the other 3%.

    If I seem grumpy or unhelpful in reply to you, or tell you you need to demonstrate more effort before you can expect help, it is likely you deserve it. Suck it up, Sunshine, and read this, this, and this before posting again.

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    Thanks for the replies!

    But I get another error in next line

    #include <iostream>
    #include <cmath>
    #include <cstdlib>

    int main(int argc, char *argv[])
    {
    double fah, cel, kel;
    char ans;
    do
    {
    cout<<"Enter the temperature in Fahrenheit: ";
    cin>>fah; // I get error here now... it says expected 'while' '(' before 'cin' and ')' before ';'

    cel = (5.0 / 9.0) * (fah - 32.0);
    kel = (cel + 273.0);

    cout<<"The temperature is "<<cel<<" degree Celsius and "<<kel<<" Kelvin."<<endl;
    cout<<endl<<endl
    <<"Do you want to do this again? ";
    cin>>ans;
    }while(ans=='Y' || ans == 'y');
    system("PAUSE");
    return EXIT_SUCCESS;
    }

  6. #6
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    You code ran just fine for me. I have no idea what you're talking about. you might add using namespace std somewhere. Also, I have no such program as "PAUSE", so there was a runtime error on that. If you just want it to wait a second before exiting, you can sleep(1000);

  7. #7
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    Quote Originally Posted by QuadraticFighte View Post
    You code ran just fine for me. I have no idea what you're talking about. you might add using namespace std somewhere. Also, I have no such program as "PAUSE", so there was a runtime error on that. If you just want it to wait a second before exiting, you can sleep(1000);
    What I wanted to do is ask the person if he/she wants to try another conversion.
    And maybe I might have messed up something while I was copying and pasting and fixing stuff at the same time...

    I'll try to program this from scratch.

    ----------------------------------------------------------EDIT---------------------------------------------------------------------

    Okay I started the program from scratch again and I get no errors and its perfectly fine until
    I get to the last part where it asks me if I want to do it again. This is what happens http://img202.imageshack.us/img202/1919/11111lj.png

    #include <cstdlib>
    #include <iostream>
    #include <cmath>

    using namespace std;

    int main(int argc, char *argv[])
    {
    char ans;
    double f,c,k;
    {
    cout<<"Enter the temperature in Fahrenheit: ";
    cin>>f;

    c = (5.0 / 9.0) * (f - 32.0);
    k = (c + 273.15);

    cout<<"The temperature is "<<c<<" degree Celsius and "<<k<<" Kelvin."<<endl;

    cout<<"Do you want to do this again? ";
    cin>>ans;
    }while(ans=='Y' || ans == 'y');
    system("PAUSE");
    return EXIT_SUCCESS;
    }
    Last edited by djayyyyy; 10-17-2010 at 03:12 PM.

  8. #8
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    That's because you left out the do in the do while loop. Right before your bracket after the line double f,c,k; On my text editor, it's line 12. What was happening was without the do, you just had a block of code and then

    Code:
    while(ans=='Y' || ans == 'y');
    This is a valid C statement which means "while ans is either y or Y do nothing" So you were stuck in an infinite loop.

  9. #9
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    Quote Originally Posted by QuadraticFighte View Post
    That's because you left out the do in the do while loop. Right before your bracket after the line double f,c,k; On my text editor, it's line 12. What was happening was without the do, you just had a block of code and then

    Code:
    while(ans=='Y' || ans == 'y');
    This is a valid C statement which means "while ans is either y or Y do nothing" So you were stuck in an infinite loop.
    SWEEEET. THANK YOU SOO MUCH for helping this newbie out

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