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arraysswift3
Kashif
Kashif

Reputation: 4632

Swift 3: Different kind of elements in an array are not acceptable

Up until Swift 2.2 I was able to do this:

for each in [myUIButton,myUILabel] {
 each.hidden = true
}

but in Swift 3 this is not acceptable because label, button etc are not the same kind of element. I have already changed line 2 to each.isHidden = true

It throws "Heterogeneous collection literal..." error. When you fix it by adding [Any], it throws "Cast 'Any' to 'AnyObject.." error.

Is there an easy fix to this problem?

Upvotes: 0

Views: 149

Answers (3)

OOPer
OOPer

Reputation: 47886

Find a common ancestor class having isHidden property, and explicitly cast to it:

for each in [myUIButton, myUILabel] as [UIView] {
    each.isHidden = true
}

Upvotes: 1

schrismartin
schrismartin

Reputation: 459

All items in your array must have a common subclass, like UIView in the case of myButton and myLabel (presumably) in order for type inference to take place. 

let label = UILabel()
let button = UIButton()
let collectionView = UICollectionView()
let tableView = UITableView()

let array = [label, button, collectionView, tableView] // Type: [UIView]

for item in array {
    item.isHidden = true
}

This code will work for your purposes.

Furthermore, if they all conform to the same protocol, you must explicitly name the protocol they conform to.

protocol Commonality { 
    func commonMethod() { ... }
}

class ThingA: Commonality { ... } // Correctly conform to Commonality
class ThingB: Commonality { ... } // Correctly conform to Commonality
class ThingC: Commonality { ... } // Correctly conform to Commonality

let array: [Commonality] = [ThingA(), ThingB(), ThingC()]

for item in array {
    item.commonMethod()
}

This should work as well, but you must explicitly name the common protocol. Otherwise (at least in my tests), it downcasts everything down to Any.

Upvotes: 1

Mike Henderson
Mike Henderson

Reputation: 2132

Tell Swift it's an [Any] array:

for each in [myButton,myLabel,x,y,z] as [Any] {
    each.hideen = true
}

But then you will get an error cause Any doesn't have a property called hideen (typo?).

Upvotes: 0

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