[julia-users] Re: Equivalent to the Python's None value for the function's default parameter value

[Steven G. Johnson]

On Friday, November 4, 2016 at 2:37:38 PM UTC-4, Alex wrote:
>
> Hi all, 
>
> I need to specify function parameter by default value None/Nothing
>

You can just use "z=nothing", which is the equivalent of the Python 
construct, and check "z===nothing".

However, z will be type-unstable, so you might want to put your actual 
computations into another lower-level function in order to keep good 
performance.