Comment by roessland

Here's a great introduction to floating-point numbers: https://tobydriscoll.net/fnc-julia/intro/floating-point.html

The next representable number after 9999999999999998.0 is 1.0e16. 9999999999999999.0 is not exactly representable in IEEE 754 floats, and will be rounded up or down.

The difference between 0.0 and 2.0 in the table is likely due to different rounding modes. I'm curious how different languages end up with different rounding modes. Is that possible to configure?

    julia> 9999999999999999.0 - 9999999999999998.0
    2.0

    julia> -9.999999999999999 + 9.999999999999998
    0.0