class People : NSObject
{
//普通属性
var firstName:String = ""
var lastName:String = ""
var nickName:String = ""
//计算属性
var fullName:String {
get {
return nickName + " " + firstName + " " + lastName
}
}
//带属性监视器的普通属性
var age:Int = 0 {
//我们需要在age属性变化前做点什么
willSet {
println("Will set an new value \(newValue) to age")
}
//我们需要在age属性发生变化后，更新一下nickName这个属性
didSet {
println("age filed changed form \(oldValue) to \(age)")
if age<10 {
nickName = "Little"
}else {
nickName = "Big"
}
}
}
