Lua implements deep copy of table tables

When a Lua variable is passed as a function parameter, values of the Boolean, string, and number types are also transmitted. Variables of the table, function, and userdata types are referenced and passed. Therefore, when table values are assigned

If a value is assigned to table B, operations on the Elements in Table B will naturally affect Table A. Of course, operations on table B itself, such as B = nil or pointing table B to another table, there is no impact on A. The following is the deep copy of Lua table.

 

Deepcopy = function (object) Local lookup_table = {} Local function _ copy (object) If type (object )~ = "Table" then return object elseif lookup_table [object] Then return lookup_table [object] end local new_table ={} lookup_table [object] = new_table for index, value in pairs (object) do new_table [_ copy (INDEX)] = _ copy (value) end return setmetatable (new_table, getmetatable (object) end return _ copy (object) endlocal Testa = {1, 2, 3, 4, 5} Local testb = testatestb [2] = "" Local testc = deepcopy (testa) testc [2] = "" for K, V in ipairs (testa) Do print ("Testa", K, V) endprint ("======================") for K, V in ipairs (testc) Do print ("testc", K, v) End

The running result is as follows:

Testa 1 1
Testa2 I wipe
Testa33
Testa44
Testa55
======================================
Testc11
Testc2
Testc33
Testc44
Testc55

Lua implements deep copy of table tables