b = b .+ 5
creates a new instance of an array, so the original array pointed to by "b"
is not changed at all.
On Thursday, May 1, 2014 7:39:14 PM UTC+8, Kaj Wiik wrote:
>
> As a new user I was surprised that even if you change the value of
> function arguments (inside the function) the changes are not always visible
> outside but in some cases they are.
>
> Here's an example:
>
> function vappu!(a,b)
> a[3]=100
> b = b .+ 5
> (a,b)
> end
>
> c = [1:5]
> d = [1:5]
>
> vappu!(c,d)
> ([1,2,100,4,5],[6,7,8,9,10])
>
> c
> 5-element Array{Int64,1}:
> 1
> 2
> 100
> 4
> 5
> d
> 5-element Array{Int64,1}:
> 1
> 2
> 3
> 4
> 5
>
>
> Should I loop over arrays explicitly, what is happening in b = b .+ 5 ?
>
> Thanks,
> Kaj
>
