虽然lua是一门小巧的胶水语言，但是它也是可以进行面向对象编程的，我们可以实现多继承和单继承，继承都是靠lua的setmetatable实现的。
类
Name = {} function Name:new(o) o = o or {} setmetatable(o, {__index = self}) return o end function Name:setName(name) self.name = name end function Name:getName() return self.Name end -- 在lua中A:b()等价于A.b(self),像标准库中string.len 等价于"xxx":len, 但是为了兼容性更倾向于写作string.len("xxx")单继承
--定义继承 SpecName = Name:New({age=25}) function SpecName:setNewName(name) if self.getAge() > 9 then self:setName(name) else error("You must give an age!") end end function SpecName:getAge() return self.age end
多继承
function search(k, plist) for i=1,#plist do if plist[i][k] ~= nil then return plist[i][k] end end end function createClass(...) local args = {...} local c = {} setmetatable(c, {__index = function(self, k) return search(k, args) end}) c.__index = c function c:new(o) o = o or {} setmetatable(o, c) return o end return c end Balance = {balance= 10} function Balance:new(o) o = o or {} setmetatable(o, {__index = self}) return o end function Balance:despoit(v) self.balance = self.balance + v end function Balance:withDraw(v) if self.balance < v then error("Bad case") else self.balance = self.balance - v end end Name={} function Name:new(o) o = o or {} setmetatable(o, {__index = self}) return o end function Name:setName(name) self.name = name end function Name:getName() return self.name end c = createClass(Balance, Name) c:despoit(100) c:withDraw(10) print(c.balance) --> 100 c:setName("wbz") print(c:getName()) --> wbz隐藏私有变量
function newAccount(initBalance) local self = {balance=initBalance} local withdraw = function(v) self.balance = self.balance - v end local deposit = function (v) self.balance = self.balance + v end local getBalance = function() return self.balance end return { withdraw=withdraw, deposit = deposit, getBalance = getBalance, } end
