How to check if an element is in an array

Swift 2, 3, 4, 5:

let elements = [1, 2, 3, 4, 5]if elements.contains(5) {    print("yes")}

contains() is a protocol extension method of SequenceType (for sequences of Equatable elements) and not a global method as inearlier releases.

Remarks:

• This contains() method requires that the sequence elementsadopt the Equatable protocol, compare e.g. Andrews's answer.
• If the sequence elements are instances of a NSObject subclassthen you have to override isEqual:, see NSObject subclass in Swift: hash vs hashValue, isEqual vs ==.
• There is another – more general – contains() method which does not require the elements to be equatable and takes a predicate as an argument, see e.g. Shorthand to test if an object exists in an array for Swift?.

Swift older versions:

let elements = [1,2,3,4,5]if contains(elements, 5) {    println("yes")}

For those who came here looking for a find and remove an object from an array:

Swift 1

if let index = find(itemList, item) {    itemList.removeAtIndex(index)}

Swift 2

if let index = itemList.indexOf(item) {    itemList.removeAtIndex(index)}

Swift 3, 4

if let index = itemList.index(of: item) {    itemList.remove(at: index)}

Swift 5.2

if let index = itemList.firstIndex(of: item) {    itemList.remove(at: index)}

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