func repeatItem<Item>(item:Item, numberOfTimes:Int) -> [Item]{
var result = [Item]()
for _ in 0..<numberOfTimes{
result.append(item)
}
return result
}
let res = repeatItem("knock", 4)
for i in res{
print(" \(i)")
}
原文：http://www.cnblogs.com/lianfu/p/5027856.html