创建空数组和空字典
var emptyArray = Array<Int>()
var emptyArray = [Int]()
var emptyArray:Array<Int> = []
var emptyDictionary = Dictionary<Int,String>()
var emptyDictionary = [Int:String]()
var emptyDictionary[Int:String] = [:]
原文：http://www.cnblogs.com/lianfu/p/4987863.html