[Go] object-oriented Implementation Method in Lua

 

Object-Oriented programming is not an idea for a language. In a process-oriented language, you can use object-oriented programming. In Lua, there is no object-oriented concept, and there is no class definition or subclass definition. However, in Lua, the idea of object-oriented can also be used to implement object-oriented class inheritance.

 

I. Copying tables is object-oriented.

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-- Object-oriented in Lua--[[  Table Copying Method object-oriented  The parameter is a table. By traversing the value of this table, an empty table is assigned, and the newly created table is returned to clone the table.]]function clone(tab)    local ins = {}    for key, var in pairs(tab) do        ins[key] = var    end    return insend --[[  Copy a table  The first parameter is the target table, and the second parameter is the table to be copied.  Assign a value to the target table by traversing the tab.]]function copy(dist,tab)    for key, var in pairs(tab) do        dist[key] = var    endend -- Define an empty table, which is equivalent to a classPeople ={} --function People.sayHi()--  print("People say hi")--end -- Define the method sayhi in the class and input a self ParameterPeople.sayHi = function (self)    print("People say hi:"..self.name)end -- DefinenewTo generate an object by cloning the people table.-- It is equivalent to a constructor in the class.People.new = function (name)    local self = clone(People)    self.name = name         return selfend --local p = clone(People)--p.sayHi()-- Generate a new objectlocal p = People.new("ZhangSan")--p.sayHi(p)--p:sayHi()-- Define an empty table, which also represents a classMan = {}-- Man constructor to implement class inheritance in LuaMan.new = function (name)    local self = People.new(name)    -- Append all the key-value pairs in man to the instance in people.    copy(self,Man)    return selfend Man.sayHello = function ()    print("Man say hello")end -- Override the sayhi method in the parent class peopleMan.sayHi = function (self)    print("Man sayHi "..self.name)end -- Create an instance of manlocal m = Man.new("Lisi")m:sayHi()

The above code has been annotated in detail, and readers need to carefully read the example given here.

 

2. Implement object-oriented functions in the form of function closures

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-- Implement object-oriented functions in the form of function closures -- Define a method. Function closures implement the concept of a class.function People(name)    local self = {}  -- Initialization method, private    local function init()        self.name = name    end       self.sayHi = function ()        print("Hello "..self.name)    end   -- Call Initialization    init()    return selfend -- Instantiate an objectlocal p = People("ZhangSan")p:sayHi() -- Implement class inheritance in the form of function closuresfunction Man(name)    local self = People(name)     --  local function init()--      --  end     self.sayHello = function ()        print("Hi "..self.name)    end         return selfendlocal m = Man("Lisi")--m:sayHello()m:sayHi()

The above two methods can achieve object-oriented, the second method of visual testing is more concise, specific use according to personal preferences.

 

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