Surprise! 0.77 * 100 == 76

Try the code:

float a = 0.77F;
int b = (int)(100 * a);
Console.WriteLine(b.ToString());

Result is 76.

What do you think about such strange .Net calculate execution ?

Nothing new! FAQ

simple solution :)

Code:

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decimal a = 0.77M;
int b = (int)(100 * a);
Console.WriteLine(b.ToString());

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can also do it with float

Code:

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                      float a = 0.77f;
                        int b =  Convert.ToInt32(100 * a);
                        console.WriteLine(b.ToString());

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Quote:

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Originally Posted by Syrix

simple solution :)

Code:

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decimal a = 0.77M;
int b = (int)(100 * a);
Console.WriteLine(b.ToString());

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Solution is not the problem.
I used Round, for example.
When I met the problem I was suppressed by so non-clear behavior of the code.
I always used double before.
Float was returned as object from DataRow element from correspond DB Field:-)
And I do not understand, why 100*0.77f == 76.99999…
Is it Microsoft or Intel?

Quote:

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Originally Posted by Alex Rest

And I do not understand, why 100*0.77f == 76.99999…
Is it Microsoft or Intel?

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it is because of the processor can never represent exactly 0.77 in binary.

Quote:

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Originally Posted by Alex Rest

And I do not understand, why 100*0.77f == 76.99999…

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That's why I posted the FAQ...