# 2 dimensional array to one dimensional

how can i make 2 dimensional array to one dimensional

Like

`arr = [[1,2], [3,4]]`
To
`one, two, three, four = something to transport`

NB: Is like numpy ravel method

You’re looking for `vec`

``````help?> vec
search: vec Vector VecOrMat VecElement BitVector DenseVector DenseVecOrMat StridedVector StridedVecOrMat AbstractVector

vec(a::AbstractArray) -> AbstractVector

Reshape the array a as a one-dimensional column vector. Return a if it is already an AbstractVector. The resulting
array shares the same underlying data as a, so it will only be mutable if a is mutable, in which case modifying one
will also modify the other.

Examples
≡≡≡≡≡≡≡≡≡≡

julia> a = [1 2 3; 4 5 6]
2×3 Array{Int64,2}:
1  2  3
4  5  6

julia> vec(a)
6-element Array{Int64,1}:
1
4
2
5
3
6

julia> vec(1:3)
1:3

``````
1 Like

`Iterators.flatten` (which you can materialize with `collect`):

``````julia> arr = [[1,2], [3,4]];

julia> it = Iterators.flatten(arr)
Base.Iterators.Flatten{Array{Array{Int64,1},1}}(Array{Int64,1}[[1, 2], [3,
4]])

julia> collect(it)
4-element Array{Int64,1}:
1
2
3
4
``````

Note though that `arr` from your example is not two dimensional; it is a one dimensional array containing one dimensional arrays.

5 Likes

thank you so much for help

thank you so much for help

``````julia> arr = [[1,2], [3,4]]
2-element Array{Array{Int64,1},1}:
[1, 2]
[3, 4]

julia> vcat(arr...)
4-element Array{Int64,1}:
1
2
3
4
``````

It’s work too…
thank you