Math.min(Math.max(num, min), max)

Re:Math.min(Math.max(num, min), max) by xxs on Thursday August 20, 2020 @01:41PM (#24226073)

Both min and max should return NaN, if any of their parameters is NaN. Sorting can be defined where to place the NaNs (head/tail) but it's largely irrelevant in this case as simply the substitution won't be permitted by any compiler.

NaN is part of IEEE754 but of course it's not a 'real' number (integer numbers don't have NaNs)

Edit: you can consider NaN (and to a degree both infinities) as an exception, once it occurs - it has to be propagated. Any operation involving NaN should be returning NaN, any operation comparing NaN to anything has to return 'false'. That includes "if (NaN == NaN)". boolean isNaN(double d) is effectively "return d != d;"

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Re:Math.min(Math.max(num, min), max) by noctune on Thursday August 20, 2020 @05:12PM (#24229045)

> Both min and max should return NaN, if any of their parameters is NaN.

That's not a given, though. IEEE 754-2008 defined min and max as returning the non-NaN parameter. They have been removed in IEEE 754-2019 though.

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Re:Math.min(Math.max(num, min), max) by xxs on Thursday August 20, 2020 @05:31PM (#24229256)

The reference to IEEE 754 is made later on, mostly to answer the question posted. I meant regular functions in C alike languages - Math.min/max - java/javascript, fmin/fmax - C++. They do the "right" thing to propagate the NaN

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