Lua Quick Start Guide

Meta tables

In Lua, meta tables can be used to modify the behavior of tables. Any table can be made into a meta table, and any table can have a meta table. Even meta tables can have their own meta tables. Meta tables change the behavior of tables using meta methods. These meta methods are functions with a specific name that affect how a table behaves.

First, create a table named meta. For now, this is a normal table. This table will have a function named __add. __add is a reserved function name. The __add function will take two arguments.

The left argument will be a table with a field called value, the right argument will be a number:

meta = { } -- Creates tablemeta.__add = function(left, right) -- adds meta method return left.value + right ...