Is Not A NAN

no-email (Damien Seguy), Damien Seguy
Tue, 18 Feb 2025 00:00:00 +0000

NAN is a special PHP constant, which represents ``not-a-number``: it is returned when a math function cannot calculate a value because it is out of its domain of application. For example, ``acos(3)`` returns ``NAN``, because ``cos()`` produces values between -1 and 1.
One special situation with NAN is that it is always different from anything.So, it cannot even compare to itself.
Also, ``NAN`` is a float.