Question about indexing into an array of arrays

New to Julia
1

Still learning about how best to use julia. This is probably more of a curious thing I noticed than anything else.

If I create an array like so:

a = [1, 2], [3, 4]]

Both of the following return what I would expect:

a[1]
a[1, 1, 1]

Why does the second line above work? Is there some functionality to being able to do this?

Thanks in advance for the help.

2

This is the explanation from the official manual:

https://docs.julialang.org/en/v1/manual/arrays/index.html#Omitted-and-extra-indices-1

more than N indices may be provided if all the indices beyond the dimensionality of the array are 1 (or more generally are the first and only element of axes(A, d) where d is that particular dimension number). This allows vectors to be indexed like one-column matrices

2 Likes