how to count number of sprites swift

问题

I'm building an app that add sprites to the screen. In several parts of my code I want to know how many sprites I have with a certain key. At the moment I implemented it in this way

var counter = 0
enumerateChildNodesWithName("box") { node, _ in
  counter = counter + 1
}
println(counter)

Is there another easier and shorter way? Thanks

回答1:

From iOS8, SKNode has subscript member that queries nodes and returns Array<SKNode>.

extension SKNode {
    subscript (name: String) -> [SKNode] { get }
}

So you can:

let count = self["box"].count
println(count)

instead of:

var counter = 0
self.enumerateChildNodesWithName("box") { _, _ in
    counter += 1
}
println(counter)

来源：https://stackoverflow.com/questions/27201797/how-to-count-number-of-sprites-swift