lua简单实现面向对象

--父类
local Person = 
{
    name = "XX"
    ,
    age = 0
    ,
    PrintName = function(self)
        print("PersonName : "..self.name)
    end
    ,
    new = function(self,name,age)
        obj = {}
        --创建并赋值实例的字段
        obj.name = name
        obj.age = age
        setmetatable(obj , {__index = self})
        return obj
    end
    ,
    PrintAge = function(self)
        print(self.name.."age"..self.age);
    end
}
--子类
local Student = 
{
    PrintName = function(self)
        print("StudentName : "..self.name)
    end
    ,
    new = function(self,name,age)
        obj = {}
        setmetatable(obj , {__index = self})
        --创建并赋值实例的字段
        obj.name = name;
        obj.age = age
        return obj
    end
}

setmetatable(Student , {__index = Person}) 
--Student.__newindex = Person

local zhangsan = Student:new("zhangsan",20)
local lisi = Person:new("lisi",25)

zhangsan:PrintName()
lisi:PrintName()
--用的是父类的方法，但使用的数据是zhangsan的name和age（用self传过去的），字段无法实现继承，需要每个实例都创建
zhangsan:PrintAge() 
lisi:PrintAge()