Why am I getting the wrong result when using float?

Question

Possible Duplicates:
Why is (double)0.6f > (double)(6/10f)?
Why is floating point arithmetic in C# imprecise?

I have the following code in C#:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace StackOverflow
{
    class Program
    {
        static void Main(string[] args)
        {
            float num1 = 17.03F;
            float num2 = 17F;
            float result = num1 - num2;
            Console.WriteLine(result);
        }
    }
}

The code works fine but I am not getting the expected result. Can someone explain why this is happening?

Answer 1

I guess you are refering to deviations cause by Floating point arithmetics. You can read about in in the provided link.

If you really need to make the calculation 100% accurate, you can use decimal instead of float.

Answer 2

Because you are using float. Float is an extremely approximate value. Always use it with an Epsilon (maximum error allowance) when comparing.

I am guessing you are getting result = 0.02999999?

Answer 3

Floating point maths is likely to contain rounding approximations, see the many duplicate questions on this site, or read here:

http://en.wikipedia.org/wiki/Floating_point

Answer 4

What about this? : What Every Computer Scientist Should Know About Floating-Point Arithmetic