Hi (This could be relevant for all kinds of functions in general, but I’ll give a specific example here). so I’m quite new to julia and currently trying to write a custom package/module with some data loading and processing functionalities for a very specific type of files. I know a bit about pos…

Instead of passing the empty string, you can directly define your default argument value: function onFile(filename::String=choose_user_file()) println("Do something with file ", filename) end

Just define two methods? julia> onFolder() = println("Do something on folder chosen_folder") onFolder (generic function with 1 method) julia> onFolder(foldername) = println("Do something on folder $foldername") onFolder (generic function with 2 methods) julia> onFolder() Do something on folder ch…

Wow okay! Thanks for the super quick reply!! :grinning: Maybe that is just the good julia programming style I am looking for! Still curious anyway if there is a built-in way to check for the number of passed arguments? (Although your solution sounds like perfectly fine, of course) Or is this ju…

An alternative solution is to use keyword arguments with nothing as a sentinel value* (although this is not exactly analogous to Matlab’s nargin): function onFile(;filename=nothing) if isnothing(filename) filename = "chosen_file.dat" end println("Do something with file ", filena…

[image] itchy00: Still curious anyway if there is a built-in way to check for the number of passed arguments? This other thread might be of interest.

Yes, thanks. I’ve actually been using this approach frequently and find it quite nice as well. But then I stumbled across the conflict with the strong typing… If I want to force filename::String I cannot assign nothing as default. (Not that it is super important for me to have that typing enforce…

Instead of passing the empty string, you can directly define your default argument value: Cool :slight_smile: I really like this idea of directly calling a function with proper return type as default value. I think this will be my favorite from now on :+1:

For simplicity, I had omitted the type requirements, but a Union is the solution for maintain a strict type parameter: function onFile(;filename::Union{Nothing,String}=nothing) if isnothing(filename) filename = "chosen_file.dat" end println("Do something with file ", filename) e…

Find out number of function arguments or if passed at all

New to Julia

rafael.guerra December 20, 2021, 4:12pm 5

This other thread might be of interest.

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Find out number of function arguments or if passed at all

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