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by codetrotter 814 days ago
So for example if you make a variable that has the value parent commenter used

100000.000000000017

And then you print it.

Does it preserve the exact value?

1 comments

Your question is ambiguous for two different reasons. First, this value is not representable as a floating-point number, so there's no way that you can even store it in a float. Second, once you have a float variable, you can print it in many different ways. So, the answer to your question is, irremediably, "it depends what you mean by exact value".

If you print your variable with the %a format, then YES, the exact value is preserved and there is no loss of information. The problem is that the literal that you wrote cannot be represented exactly. But this is hardly a fault of the floats. Ints have exactly the same problem:

    int x = 2.5;   // x gets the value 2
    int y = 7/3;   // same thing
So in other words, is it fair to say that this situation is not much different from what you get with Python?