# setdiff

setdiff(s1,s2)

Construct the set of elements in `s1`

but not `s2`

. Maintains order with arrays. Note that both arguments must be collections, and both will be iterated over. In particular, `setdiff(set,element)`

where `element`

is a potential member of `set`

, will not work in general.

## Examples

```
julia> setdiff(Set(1,2,3,4),Set(2,3,5))
Set{Int64}({4,1})
```

```
julia> setdiff(Set(2,3),Set(2,3))
Set{Int64}({})
```

```
julia> all = [10:-1:1];
julia> odd = [1:2:10];
julia> even = setdiff(all, odd) # note the ordering of elements in result
5-element Array{Int64,1}:
10
8
6
4
2
```

## See Also

complement, complement!, intersect, intersect!, issubset, selectperm, selectperm!, Set, setdiff, setdiff!, symdiff, union, union!,## User Contributed Notes

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