In Objective-C, Euler's number?

How could开发者_如何学Python Euler's number (e) be implemented in Objective-C?

M_E, declared in <math.h>, is the value of the Euler number. You can use the exp() function, also declared in math.h to calculate e^x.

I think the constant M_E defined in <math.h> is what you are looking for.