Basic Introduction Question 1: bad example of shallow vs deep copy

[dmaniry]

Question 1 threw me off when it introduced the concept of shallow vs deep copy, because the example would actually work with a shallow copy. It doesn't work with a plain assignment and then introduces deepcopy as a fix even though copy (which was introduced before) would have the same effect. The example should be reworked to actually require deepcopy or make a clearer distinction of the three options. Also there is a minor issue with the cell execution order being confusing, because you have to go 2 cells back to reinitialize a to see the fix working.

[ChrisRackauckas]

Yeah, the example should be more like:

a = Vector{Vector{Float64}}(undef,3)
a[1] = [1;2;3]
a[2] = [1;2]
a[3] = [3;4;5]
a

b = copy(a)
b[1][1] = 6
a

c = deepcopy(a)
c[1][1] = 10
a