Book Image

Lua Quick Start Guide

By : Gabor Szauer
4 (1)
Book Image

Lua Quick Start Guide

4 (1)
By: Gabor Szauer

Overview of this book

Lua is a small, powerful and extendable scripting/programming language that can be used for learning to program, and writing games and applications, or as an embedded scripting language. There are many popular commercial projects that allow you to modify or extend them through Lua scripting, and this book will get you ready for that. This book is the easiest way to learn Lua. It introduces you to the basics of Lua and helps you to understand the problems it solves. You will work with the basic language features, the libraries Lua provides, and powerful topics such as object-oriented programming. Every aspect of programming in Lua, variables, data types, functions, tables, arrays and objects, is covered in sufficient detail for you to get started. You will also find out about Lua's module system and how to interface with the operating system. After reading this book, you will be ready to use Lua as a programming language to write code that can interface with the operating system, automate tasks, make playable games, and much more. This book is a solid starting point for those who want to learn Lua in order to move onto other technologies such as Love2D or Roblox. A quick start guide is a focused, shorter title that provides a faster paced introduction to a technology. It is designed for people who don't need all the details at this point in their learning curve. This presentation has been streamlined to concentrate on the things you really need to know.
Table of Contents (10 chapters)

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 table
meta.__add = function(left, right) -- adds meta method
return left.value + right -- left is assumed to be a table.
end

Next, make a table called container. The container table will have a variable called value, with a...