Why is NaN not equal to NaN
14 visualizzazioni (ultimi 30 giorni)
Mostra commenti meno recenti
Why is this not true?
NaN==NaN
ans =
0
0 Commenti
Risposta accettata
Cedric
il 16 Gen 2013
Modificato: Cedric
il 16 Gen 2013
Most times, you don't want this test to return true indeed. Imagine testing a==b and having a true result when both a and b are undefined; this would make little sense. It is the same with NaN.
While it is not the original question, note that you can test equality assuming NaN 's are equal:
But with that you usually want to test if "behaviors" are the same (and not equality per se), e.g. if two functions return the same number or both NaN do something, else do something else.
Più risposte (1)
Matt J
il 16 Gen 2013
Modificato: Matt J
il 16 Gen 2013
Because equality is a notion applied to numbers. How can 2 things be equal when they are not numbers?
7 Commenti
math man
il 17 Set 2021
You might wonder, though, why NaN ~= NaN returns true?
That is, if they are not numbers why are they compared in this case to give a misleading result?
Vedere anche
Categorie
Scopri di più su Logical in Help Center e File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!