# 3d array Literal
**URL:** https://discourse.julialang.org/t/3d-array-literal/35310
**Category:** New to Julia
**Tags:** question
**Created:** [February 29, 2020, 12:03am UTC](https://discourse.julialang.org/t/3d-array-literal/35310 "2020-02-29T00:03:53Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Sijun](https://discourse.julialang.org/u/Sijun)
#### Post date: [February 29, 2020, 12:03am UTC](https://discourse.julialang.org/t/3d-array-literal/35310/1 "2020-02-29T00:03:53Z")
In C, 3d array literal is written as
```julia
int arr[3][3][3]=
{
{
{11, 12, 13},
{14, 15, 16},
{17, 18, 19}
},
{
{21, 22, 23},
{24, 25, 26},
{27, 28, 29}
},
{
{31, 32, 33},
{34, 35, 36},
{37, 38, 39}
},
};
```
I wonder how to write 3d array literal in Julia and higher dimensional array in general.
I tried below but it produces only 2d array:
```julia
a = [
[1 2 3; 4 5 6];
[11 12 13; 14 15 16];
[21 22 23; 24 25 26];
]
```
6×3 Array{Int64,2}:
1 2 3
4 5 6
11 12 13
14 15 16
21 22 23
24 25 26
```julia
```
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [February 29, 2020, 6:55am UTC](https://discourse.julialang.org/t/3d-array-literal/35310/2 "2020-02-29T06:55:27Z")
I don’t think there is syntax for this, see
[https://github.com/JuliaLang/julia/pull/33697](https://github.com/JuliaLang/julia/pull/33697)
Just construct it — eg `cat(...; dims = 3)`.
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [February 29, 2020, 7:53am UTC](https://discourse.julialang.org/t/3d-array-literal/35310/3 "2020-02-29T07:53:37Z")
Or, alternatively, provide a matrix/vector and `reshape`.
---
### Author:  [@Sijun](https://discourse.julialang.org/u/Sijun)
#### Post date: [February 29, 2020, 9:43am UTC](https://discourse.julialang.org/t/3d-array-literal/35310/4 "2020-02-29T09:43:54Z")
That’s right. I tried `permutedims!(reshape(1:8, (2,2,2)), (2,1,3))` and it works well indeed! A bit cumbersome due to column-major vs row-major conversion 🙂 It should be really great if syntax for multidimensional array is merged in near future.
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [February 29, 2020, 9:52am UTC](https://discourse.julialang.org/t/3d-array-literal/35310/5 "2020-02-29T09:52:10Z")
TBH, while I agree that it is nice when you need it, it is not something that is used so often that it needs its own specific syntax.
Something like
```julia
"Concatenate along an extra first dimension."
function upcat(a::AbstractArray{T,N}, rest...) where {T,N}
@assert all(ndims.(rest) .== N)
permutedims(cat(a, rest...; dims = N + 1), (N + 1, ntuple(identity, N)...))
end
A = upcat([1 2 3; 4 5 6],
[11 12 13; 14 15 16],
[21 22 23; 24 25 26])
```
would be more generic and allow nesting to arbitrary dimensions (warning: not well-tested, optimized, etc).
---
### Author:  [@Yannik](https://discourse.julialang.org/u/Yannik)
#### Post date: [July 8, 2025, 8:07am UTC](https://discourse.julialang.org/t/3d-array-literal/35310/6 "2025-07-08T08:07:25Z")
The feature was merged a few years ago for anyone finding this thread. Here is a comment describing it [Syntax for multidimensional arrays by BioTurboNick · Pull Request #33697 · JuliaLang/julia · GitHub](https://github.com/JuliaLang/julia/pull/33697#issuecomment-797029617)
example:
```julia
julia> [1 2 3
4 5 6
;;;
7 8 9
0 1 2]
2×3×2 Array{Int64, 3}:
[:, :, 1] =
1 2 3
4 5 6
[:, :, 2] =
7 8 9
0 1 2
```
or
```julia
julia> [1 2 3; 4 5 6;;; 7 8 9; 10 11 12]
2×3×2 Array{Int64, 3}:
[:, :, 1] =
1 2 3
4 5 6
[:, :, 2] =
7 8 9
10 11 12
```
Note: `[1 ;; 2]` is treated as `[1 ; ; 2]` so double column do not work
---
### Author:  [@gustaphe](https://discourse.julialang.org/u/gustaphe)
#### Post date: [July 8, 2025, 3:41pm UTC](https://discourse.julialang.org/t/3d-array-literal/35310/7 "2025-07-08T15:41:51Z")
I’m not sure what you mean by “double column do not work”, but I think showcasing the use of `;;` is important to explain why `;;;` has three semicolons.
`;` separates items within a column (along dimension 1), `;;` separates columns (along dimension 2), and `;;;` separates pages (along dimension 3) etc. So that array can also be written as
```julia
[1; 4;; 2; 5;; 3; 6;;; 7; 10;; 8; 11;; 9; 12]
```
(the chosen numbers make this look a bit arbitrary, but we could have entered the numbers column by column to begin with and gotten
```julia
[1; 2;; 3; 4;; 5; 6;;; # etc
```
)