sign
Returns the sign of the given value x :
-
-1.0
if the value is negative, - zero if the value is zero,
-
1.0
if the value is positive
Special case:
-
sign(NaN)
isNaN
Returns the sign of this value:
-
-1.0
if the value is negative, - zero if the value is zero,
-
1.0
if the value is positive
Special case:
-
NaN.sign
isNaN