area and circumference of a circle

[heights]

Hi

I have written a code but it's not working. It does compile. Please remember I'm a beginner. In the bold processing statements I have defined what "A" and "C" are. So if the area is greater or equal to 0, then display the value. Actually I don't want to use the processing statements again in if's cout. Please help me. Thanks a lot.

// program to calculate area of a circle

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

using namespace std;

int main()

{
    float R, A, C;
    cout << "Enter the radius R = ";
    cin >> R;
    A = 3.142*R*R;
    C = 2*3.142*R;
    if (R >= 0)
       {
       cout << "Area = A" << endl;
       cout << "Circumference = C" << endl;
        }
    else
        cout << "Invalid R" << endl;
    system ("PAUSE");
}

[Alterah]

       cout << "Area = A" << endl;
       cout << "Circumference = C" << endl;

These two lines don't do what you think. You need to actually output A and C...here you are merely outputting two strings (no numbers). The strings being "Area = A" and "Circumference = C" How would you normally output just a number to the screen?

[heights]

       cout << "Area = A" << endl;
       cout << "Circumference = C" << endl;

These two lines don't do what you think. You need to actually output A and C...here you are merely outputting two strings (no numbers). The strings being "Area = A" and "Circumference = C" How would you normally output just a number to the screen?

Hi Alterah

Thanks for pointing this out. I have corrected it.

 if (R >= 0)
       {
       cout << "Area = " << A << endl;
       cout << "Circumference = " << C << endl;
        }

[Alterah]

The only other things I would point out (they won't effect what your code outputs) is to line up the closing brace on the if statement with the opening brace. And, also use braces for the else clause. I know they are technically required for one line statements, but it is good to get into the practice, and I think it makes the code more readable.

[heights]

The only other things I would point out (they won't effect what your code outputs) is to line up the closing brace on the if statement with the opening brace. And, also use braces for the else clause. I know they are technically required for one line statements, but it is good to get into the practice, and I think it makes the code more readable.

Thank you, Alterah. Yes, you are right, one has to be consistent.

But sometimes my tab doesn't really align them well so I have space and backspace buttons manually. Suppose the character (let's say a brace located above the line where I'm at) I'm seeking alignment with, then pressing tab doesn't align it.

As a result I have to check the column number of the character, and use space and backspace buttons for alignment purposes.

Hope you could understand what I'm saying.

Regards
H

[Alterah]

That is probably an issue with Dev-C++. It truly is obselete. I would seriously consider updating to either Visual Studio C++ or Code::Blocks.