On Monday, November 7, 2016 at 9:02:44 AM UTC-5, Fred wrote:
>
> Hi,
>
> I have many problems to build arrays with the keys of a dictionary except
> for the simple situation :
>
> a = [uppercase(key) for key in keys(dict)] # works fine
>
> If I try to select the keys with more complex criteria like :
>
> dict = Dict("a" => 1, "b" => 2, "c" => 3, "d" => 4, "e" => 5)
>
> a = Array{String}
>
This is a mistake: you just assigned "a" to an array *type*, not an array
*instance*. It should be a = Array{String}().
In Julia 0.5, you can also just do:
[k for k in keys(dict) if dict[k] < 2]
