Nan is designed to propagate through all calculations, infecting them like a virus, so if somewhere in your deep, complex calculations you hit upon a nan, you don't bubble out a seemingly sensible answer Otherwise by identity nan/nan should equal 1, along with all the other consequences like (nan/nan)==1, (nan*1)==nan, etc. 182 i just came across this technique in the book effective javascript that is pretty simple Since nan is the only javascript value that is treated as unequal to itself, you can always test if a value is nan by checking it for equality to itself: In the land of real numbers, there are some operations that usually can be performed, but sometimes don't have a defined result For example, let's look at logarithms.
Float('nan') represents nan (not a number) But how do i check for it? 37 it's a special case, nan is the only thing in javascript not equal to itself Although the other answers about strings vs the nan object are right too. In my opinion, the value read to that dictionary entry should be none but instead nan is assigned Surely none is more descriptive of an empty cell as it has a null value, whereas nan just says that the value read is not a number
Why is nan assigned instead of none? In numpy there are nan, nan and nan What's the sense of having all three, do they differ or any of these can be used interchangeably? Javascript automatic type conversion convert nan into number, so checking if a number is not a number will always b false And nan !== nan will be true. I would like to know why some languages like r has both na and nan
What are the differences or are they equally the same Is it really needed to have na?
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