Lua Coding Tips Sheet

Working with the insertion into IOS programming first challenge was to sort through  all the different code.

I now have a library of  books on C,  C+, Objective C, and Lua

All Similar

All Different

The main thing (I have found)  to move between each programming language is the ability to forget or separate  one syntax and pickup another.

This is my Lua Quick Reference coding Tips sheet for review when I need a jump start

In doing serious brain dumps with C and objective C and then retooling for Lua your brain starts to seize and melt and then I found the short converted German to english guide (link below) For me to understand Ansca Corona I needed to be a little clearer on Lua and  once I went back and read through the beginners guide  (Written by LUA I understood better what is going on in the code.

Essentially Lua is Algebra  Statements with rules

With Algebra you can and do have several ways to get to the same answer that being so it is important to organize your thoughts and if things work use the same methods so

If all else fails go back and read this Lua Guide

Programming in Lua manual is  on line 1st Edition by Roberto Ierusalimschy   Make sure if you purchase the book since first edition is online you purchase the  updated  Programming in Lua 2nd edition ISBN 8590379825

Confusing  Same Name just Edition changes you want the Dark Blue Cover not the Light Blue

Some hard set Rules and at the bottom are rules – for me to make coding  easier to  read and stick to rules I try to follow

Variables – Names
It doesn’t matter how we call a variable. However, there are some rules to consider.

• A variable name has to start either with a letter (character) or an underscore.
• Variables are case sensitive   Upper case and lower case in a name of a variable is very important: player1 is not equal to Player1
• Only characters, numbers an underscores are allowed.
• Reserved words are not allowed for using as name for a variable.
• Great Coding includes Comments  – Is the Lua symbol to identify what follows is a comment – A comment in Lua starts with a double-hyphen and runs to the end of the line. –[[ Multi-line strings & comments are adorned with double square brackets. ]]

Variables can be Global or Local

A local variable only exists in the block it was created in

Variables have the following values

• NIL (nothing)(empty)(not existing)
• numbers
• characters (letters, words, etc.)
• conditions (true/false)(yes/no)(1/0)
• functions (as special case of a block)
• tables (with a lot of others variables stored inside)

FUNCTIONS

Functions are variables that are doing something when they are called.

Functions will be started either with

Calculate = function()
– or with
function Calculate()

and they will be finished with

    end

Tables
Tables are variables storing other variables inside them.

Chunks
The unit of Execution of Lua is called a chunk.

Achunk is simply a sequence of statements  huge tip is chunks flow they are executed sequentially

Chunks

Can define varibles, recieve arguments and return values

My Rules to Follow (Not Rules of LUA)

• In general my variables will start with a lower case
• Names of my functions will start with an upper case
• Parameters (we will learn about later) will be started with an underscore
• Every new word inside a name of a variable will have an upper case letter.
• Tables are variables storing other variables inside them.