Why can't I iterate through an NSArray?

Question

In Objective-C I always did this:

for (SKSpriteNode *sprite in sprites.children) {

   //Do something for every sprite.
}

But when I try to do the same thing in swift I get problems.

I do it like this:

 for sprite: SKSpriteNode in sprites.children {

   //Do something for every sprite.
  }

This gives me the error: Reference to generic method 'children' is ambiguous without more context

I'm fairly new to swift, I just started learning yesterday, so what am I doing wrong?

error messages with Swift are sometimes strange... have you tried instead `for sprite in sprites.children as SKSpriteNode { ... ` ? — Volker, Apr 19 '15 at 07:53
Try like this - for obj : AnyObject in sprites.children { if let xyz = obj as? SKSpriteNode { } } — Uttam Sinha, Apr 19 '15 at 08:08

score 1 · Accepted Answer · answered Apr 19 '15 at 08:14

1

You have to cast the array. I dont know why apple did like this but this is the way to do it:

for sprite in sprites.children as [SKSpriteNode] {
    // If you know for sure that every child is an SKSpritNode
}

// OR

for child in sprites.children {
    if let sprite = child as? SKSpriteNode {
        // To be 100% sure
    }
}

answered Apr 19 '15 at 08:14

Arbitur

38,684
22
91
128

it said i had to ad ! after as in the first for loop – Squid Apr 19 '15 at 08:53
why? because you cannot iterate over an unknown object. – Sulthan Apr 19 '15 at 08:54
You probably have xcode 6.3 with Swift 1.2 (https://developer.apple.com/swift/blog/?id=22). My answer is in 1.1. – Arbitur Apr 19 '15 at 09:09

Why can't I iterate through an NSArray?

1 Answers1