20.Swift懒加载lazy

// Swift懒加载使用lazy关键字来修饰属性

// 在属性后面跟= {}进行具体的赋值

// 只会被加载一次

lazy var names : [String]? = {

// () -> ([String]) in

print("加载数据")

return ["why", "lnj", "lmj"]

}()

override func viewDidLoad() {

super.viewDidLoad()

}

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {

print(names);

print(names);

print(names);

print(names);

}