ios - Spawn enemies does not work good in spritekit / swift -

i want sequentially spawn enemies. wrote code that, can't understand why 2 of first enemies appears on right position, , rest of them spawn on wrong positions. here code:

func adddoor() {     in 0...1 {         let doorsprite = skspritenode(imagenamed: "door")         doorsprite.name = "door\(i)"         if == 0 {             doorsprite.position = cgpointmake(self.frame.size.width / 2.0 - 40.0 - doorsprite.frame.size.width, self.frame.size.height - doorsprite.frame.size.height / 2.0)         } else {             doorsprite.position = cgpointmake(self.frame.size.width / 2.0 + 40.0 + doorsprite.frame.size.width, self.frame.size.height - doorsprite.frame.size.height / 2.0)         }         gamelayer.addchild(doorsprite)     } }  func enemyspawn() {     in 0..<15 {         let sprite = enemy(imagenamed: "enemy")         sprite.name = "enemy\(i)"          let randdoor = int(arc4random_uniform(2))              if randdoor == 0 {                 if let door = gamelayer.childnodewithname("door\(randdoor)") {                     sprite.position = cgpointmake((door.position.x - door.frame.size.width / 2.0) + spawnpoint(uint32(door.frame.size.width - sprite.frame.size.width)) + sprite.frame.size.width / 2.0, door.position.y)                 }             } else {                 if let door = homelayer.childnodewithname("door\(randdoor)") {                     sprite.position = cgpointmake((door.position.x - door.frame.size.width / 2.0) + spawnpoint(uint32(door.frame.size.width - sprite.frame.size.width)) + sprite.frame.size.width / 2.0, door.position.y)                 }             }         }          enemieslayer.runaction(skaction.waitforduration(nstimeinterval(i)), completion: {             self.enemieslayer.addchild(sprite)         })      } }  func spawnpoint(num: uint32) -> cgfloat {     let randomspawn: cgfloat = cgfloat(arc4random_uniform(num))     return randomspawn } 

for 1 thing, logic in both if , else blocks same.

i'm not quite sure you're trying here or how randdoor variable supposed used, whole if - else block isn't doing anything.