= Julia Arrays =

Julia supports '''single-''' and '''multi-dimensional arrays'''.

<<TableOfContents>>

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== Declaration ==

A single-dimensional array is called a '''vector'''.

{{{
julia> [1,2,3]
3-element Vector{Int64}:
 1
 2
 3
}}}

Arrays take the common type of all their elements. If the elements are not of the same type but have a common [[Julia/DataTypes#Promotion|promotion type]], the elements are recast.

{{{
julia> [1, 2.3, 4//5]
3-element Vector{Float64}:
 1.0
 2.3
 0.8
}}}

Elements can also be explicitly recast at declaration of an array.

{{{
julia> Float32[1, 2.3, 4//5]
3-element Vector{Float32}:
 1.0
 2.3
 0.8
}}}

If elements are delimited by single semicolons (`;`) or newlines, they are '''vertically concatenated'''. This usually still results in a vector.

{{{
julia> [1:2; 4:5]
4-element Vector{Int64}:
 1
 2
 4
 5

julia> [1:2
        4:5
        6]
5-element Vector{Int64}:
 1
 2
 4
 5
 6
}}}

If elements are delimited by tabs or spaces or double semicolons, they are '''horizontally concatenated'''. This usually creates a '''matrix''', a multi-dimensional array.

{{{
julia> [1:2  4:5  7:8]
2×3 Matrix{Int64}:
 1  4  7
 2  5  8

julia> [1 2 3]
1×3 Matrix{Int64}:
 1  2  3
}}}



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