Removing object from array in Swift 3
var a = ["one", "two", "three", "four", "five"]
// Remove/filter item with value 'three'
a = a.filter { $0 != "three" }
The Swift equivalent to NSMutableArray
's removeObject
is:
var array = ["alpha", "beta", "gamma"]
if let index = array.firstIndex(of: "beta") {
array.remove(at: index)
}
if the objects are unique. There is no need at all to cast to NSArray
and use indexOfObject:
The API index(of:
also works but this causes an unnecessary implicit bridge cast to NSArray
.
Of course you can write an extension of RangeReplaceableCollection
to emulate the function. But due to value semantics you cannot name it removeObject
.
extension RangeReplaceableCollection where Element : Equatable {
@discardableResult
mutating func remove(_ element : Element) -> Element?
{
if let index = firstIndex(of: element) {
return remove(at: index)
}
return nil
}
}
Like remove(at:
it returns the removed item or nil
if the array doesn't contain the item.
If there are multiple occurrences of the same object use filter
. However in cases like data source arrays where an index is associated with a particular object firstIndex(of
is preferable because it's faster than filter
.
Update:
In Swift 4.2+ you can remove one or multiple occurrences of beta
with removeAll(where:)
:
array.removeAll{$0 == "beta"}