mutability.jl

julia> a = function(x)
       x[1] = 0
       end
# function

julia> x = [3,3]
2-element Int64 Array:
 3
 3

julia> a(x)
0

julia> x
2-element Int64 Array:
 0
 3

julia> b = function(x)
       x = 0
       end
# function

julia> myn = 4
4

julia> b(myn)
0

julia> myn
4