How to check if an element is in an array

Question

In Swift, how can I check if an element exists in an array? Xcode does not have any suggestions for contain, include, or has, and a qu

Answer 1

Use this extension:

extension Array {
    func contains<T where T : Equatable>(obj: T) -> Bool {
        return self.filter({$0 as? T == obj}).count > 0
    }
}

Use as:

array.contains(1)

Updated for Swift 2/3

Note that as of Swift 3 (or even 2), the extension is no longer necessary as the global contains function has been made into a pair of extension method on Array, which allow you to do either of:

let a = [ 1, 2, 3, 4 ]

a.contains(2)           // => true, only usable if Element : Equatable

a.contains { $0 < 1 }   // => false

Answer 2

Here is my little extension I just wrote to check if my delegate array contains a delegate object or not (Swift 2). :) It Also works with value types like a charm.

extension Array
{
    func containsObject(object: Any) -> Bool
    {
        if let anObject: AnyObject = object as? AnyObject
        {
            for obj in self
            {
                if let anObj: AnyObject = obj as? AnyObject
                {
                    if anObj === anObject { return true }
                }
            }
        }
        return false
    }
}

If you have an idea how to optimize this code, than just let me know.

Answer 3

Swift

If you are not using object then you can user this code for contains.

let elements = [ 10, 20, 30, 40, 50]

if elements.contains(50) {

   print("true")

}

If you are using NSObject Class in swift. This variables is according to my requirement. you can modify for your requirement.

var cliectScreenList = [ATModelLeadInfo]()
var cliectScreenSelectedObject: ATModelLeadInfo!

This is for a same data type.

{ $0.user_id == cliectScreenSelectedObject.user_id }

If you want to AnyObject type.

{ "\($0.user_id)" == "\(cliectScreenSelectedObject.user_id)" }

Full condition

if cliectScreenSelected.contains( { $0.user_id == cliectScreenSelectedObject.user_id } ) == false {

    cliectScreenSelected.append(cliectScreenSelectedObject)

    print("Object Added")

} else {

    print("Object already exists")

 }

Answer 4

An array that contains a property that equals to

yourArray.contains(where: {$0.propertyToCheck == value })

Returns boolean.

Answer 5

I used filter.

let results = elements.filter { el in el == 5 }
if results.count > 0 {
    // any matching items are in results
} else {
    // not found
}

If you want, you can compress that to

if elements.filter({ el in el == 5 }).count > 0 {
}

Hope that helps.

---

Update for Swift 2

Hurray for default implementations!

if elements.contains(5) {
    // any matching items are in results
} else {
    // not found
}

Answer 6

Just in case anybody is trying to find if an indexPath is among the selected ones (like in a UICollectionView or UITableView cellForItemAtIndexPath functions):

    var isSelectedItem = false
    if let selectedIndexPaths = collectionView.indexPathsForSelectedItems() as? [NSIndexPath]{
        if contains(selectedIndexPaths, indexPath) {
            isSelectedItem = true
        }
    }