Lua面向对象 --- 多态

多态，简单的理解就是事物的多种形态。专业的术语说就是：同一个实现接口，使用不同的实例而执行不同的操作。

工程结构:

BaseRoom.lua:

 1 BaseRoom = {}
 2 
 3 function BaseRoom:new()    
 4     self = {}
 5     setmetatable(self,BaseRoom)
 6     BaseRoom.__index = BaseRoom
 7     return self
 8 end
 9 
10 --对该方法的调用体现了多态
11 function BaseRoom:Size()
12     return 100
13 end
14 
15 function BaseRoom:GetSize()
16     return self:Size()*2
17 end
18 
19 return BaseRoom

MarryRoom.lua:

 1 require "BaseRoom"
 2 
 3 MarryRoom = {}
 4 
 5 function MarryRoom:new()
 6     setmetatable(MarryRoom, BaseRoom)
 7     BaseRoom.__index = BaseRoom
 8 
 9     self = {}
10     setmetatable(self,MarryRoom)
11     MarryRoom.__index = MarryRoom
12 
13     return self
14 end
15 
16 --对该方法的调用提现了多态
17 function MarryRoom:Size()
18     return 50
19 end
20 
21 return MarryRoom

StarRoom.lua:

 1 require "BaseRoom"
 2 
 3 StarRoom = {}
 4 
 5 function StarRoom:new()
 6     setmetatable(StarRoom,BaseRoom)
 7     BaseRoom.__index = BaseRoom
 8 
 9     self = {}
10     setmetatable(self,StarRoom)
11     StarRoom.__index = StarRoom
12 
13     return self
14 end
15 
16 --对该方法的调用体现了多态
17 function StarRoom:Size()
18     return 20
19 end
20 
21 return StarRoom

码云上的相关工程:https://gitee.com/luguoshuai/LearnLua