Randomize image in array in sprite kit swift. -

i wondering if show me how make can spawn random image missiles. right using 1 image called "meteor", have few more images show , randomize. know need put them in array , create arc random. have done sound i'm not sure how images. code far.

var lastmissileadded : nstimeinterval = 0.0 let missilevelocity : cgfloat = 4.0  func addmissile() {     // initializing missile node     var missile = skspritenode(imagenamed: "meteor")     missile.setscale(0.44)      // adding spritekit physics body collision detection     missile.physicsbody = skphysicsbody(rectangleofsize: missile.size)     missile.physicsbody?.categorybitmask = uint32(obstaclecategory)     missile.physicsbody?.dynamic = true     missile.physicsbody?.contacttestbitmask = uint32(shipcategory)     missile.physicsbody?.collisionbitmask = 0     missile.physicsbody?.usesprecisecollisiondetection = true     missile.name = "missile"      // selecting random y position missile     var random : cgfloat = cgfloat(arc4random_uniform(300))     missile.position = cgpointmake(self.frame.size.width + 20, random - 20)     self.addchild(missile) }  func moveobstacle() {     self.enumeratechildnodeswithname("missile", usingblock: { (node, stop) -> void in         if let obstacle = node as? skspritenode {             obstacle.position = cgpoint(x: obstacle.position.x - self.missilevelocity, y: obstacle.position.y)             if obstacle.position.x < 0 {                 obstacle.removefromparent()             }         }      }) } 

all need name them meteor0, meteor1 , meteor2 , use string interpolation create node random image:

var missile = skspritenode(imagenamed: "meteor\(arc4random_uniform(3))")