Removing object from array in Swift 3

Question

In my application I added one object in array when select cell and unselect and remove object when re-select cell. I used that code but give me error.

extension Array {     func indexOfObject(object : AnyObject) -> NSInteger {         return (self as NSArray).indexOfObject(object)     }      mutating func removeObject(object : AnyObject) {         for var index = self.indexOfObject(object); index != NSNotFound; index = self.indexOfObject(object) {             self.removeAtIndex(index)         }     } }  class MyViewController: UITableViewController {     var arrContacts: [Any] = []     var contacts: [Any] = []      func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {         arrContacts.removeObject(contacts[indexPath.row])     } } 

It gives me 2 error like that:

C-style for statement has been removed in Swift 3 Value of type '[Any]' has no member 'removeObject' 

Answer 1

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"}