I was wondering if someone could explain this line from Chapter 9 (Page 240) a little bit further.
let labelNode = contact.bodyA.categoryBitMask == PhysicsCategory.Label ? contact.bodyA.node : contact.bodyB.node
I was able to complete the challenge first without the guidelines as suggested. I decided to take it one step further, and try it again with the suggested directions. I was able to implement it and complete the challenge, but was wondering if someone could offer a bit more detail about this.
Thanks.