# union

union(s1,s2...) âˆª(s1,s2...)

Construct the union of two or more sets. Maintains order with arrays.

## Examples

julia> set1 = Set(3, 4, 5, 6)
set2 = Set(1, 3, 4)
union(set1,set2)
Set{Int64}({4,3,5,6,1})
julia> a = Set("Hello")
Set{Char}({'e','H','l','o'})

julia> b = Set([10:-1:6])
Set{Int64}({7,9,10,8,6})

julia> union(a,b)
Set{Integer}({7,9,10,'e','H','l',8,'o',6})
julia> union([1, 2, 3], [3, 4, 5])
5-element Array{Int64,1}:
1
2
3
4
5
julia> union([1, 2, 3], [3, 4, 5], [6, 7, 8])
8-element Array{Int64,1}:
1
2
3
4
5
6
7
8
julia> union([1, 2, 3], [3, 4, 5], [5, 6, 7])
7-element Array{Int64,1}:
1
2
3
4
5
6
7
julia> union([1, 2, 3], [4, 5, 6])
6-element Array{Int64,1}:
1
2
3
4
5
6
julia> union(["apple", "banana"], ["banana", "orange"])
3-element Array{String,1}:
"apple"
"banana"
"orange"
julia> union(Set([1, 2, 3]), Set([3, 4, 5]))
Set{Int64} with 5 elements:
4
2
3
5
1

Common mistake example:

julia> union([1, 2, 3], 4, 5)
ERROR: MethodError: no method matching union(::Array{Int64,1}, ::Int64, ::Int64)

In this example, the union function is expecting sets or arrays as arguments and not individual elements. Make sure to pass sets or arrays as arguments to the union function.