Introduction to Programming in Lua

Lua is a lightweight, embeddable scripting language known for its simplicity, speed, and flexibility. It is widely used in game development (e.g., Roblox, World of Warcraft), embedded systems, and as a general-purpose scripting language. Lua's minimalistic design makes it easy to learn, while its powerful features like tables and coroutines make it highly versatile.

This guide will introduce you to the fundamentals of Lua programming, helping you write clean and efficient scripts for a variety of applications.

Table of Contents

1. What is Lua?
2. Setting Up Your Environment
3. Variables and Data Types
4. Operators and Expressions
5. Conditional Statements
6. Loops
7. Functions
8. Tables
9. Strings
10. Coroutines

What is Lua?

Lua is a lightweight, high-level scripting language designed for embedded systems and extensibility. It is often used as a scripting language in games, applications, and tools.

1-- Example: Your first Lua program
2print("Hello, Lua Programming!")

Setting Up Your Environment

To write and run Lua programs, you need the Lua interpreter installed on your system. You can download it from the official Lua website.

1# Example: Running a Lua script
2lua script.lua

Variables and Data Types

Lua is dynamically typed, meaning you don't need to declare variable types explicitly. Common data types include nil, boolean, number, string, and table.

1-- Example: Declaring variables
2local age = 25
3local height = 5.9
4local name = "Alice"
5local isStudent = true
6
7print("Name:", name, "Age:", age, "Height:", height)

Operators and Expressions

Lua includes arithmetic, relational, and logical operators to perform operations on data.

1-- Example: Using operators
2local a = 10
3local b = 5
4local sum = a + b -- 15
5local isGreater = a > b -- true
6
7print("Sum:", sum, "Is Greater:", isGreater)

Conditional Statements

Conditional statements like if, elseif, and else allow you to execute code based on certain conditions.

1-- Example: Conditional statement
2local age = 18
3
4if age >= 18 then
5    print("You are an adult.")
6else
7    print("You are a minor.")
8end

Loops

Lua supports for, while, and repeat-until loops for repeating blocks of code.

1-- Example: For loop
2for i = 1, 5 do
3    print("Iteration:", i)
4end

Functions

Functions are reusable blocks of code that perform a specific task. You can define functions using the function keyword.

1-- Example: Function
2local function add(a, b)
3    return a + b
4end
5
6local result = add(5, 10)
7print("Result:", result) -- 15

Tables

Tables are Lua's primary data structure, used to represent arrays, dictionaries, and more.

1-- Example: Table
2local person = {
3    name = "Alice",
4    age = 25,
5    isStudent = true
6}
7
8print("Name:", person.name, "Age:", person.age)

Strings

Lua provides powerful string manipulation capabilities, including pattern matching and concatenation.

1-- Example: String manipulation
2local greeting = "Hello"
3local name = "Alice"
4local message = greeting .. ", " .. name .. "!"
5
6print(message) -- Hello, Alice!

Coroutines

Coroutines are a unique feature of Lua that allow cooperative multitasking. They enable you to pause and resume functions.

 1-- Example: Coroutine
 2local function task()
 3    print("Task started")
 4    coroutine.yield()
 5    print("Task resumed")
 6end
 7
 8local co = coroutine.create(task)
 9coroutine.resume(co) -- Task started
10coroutine.resume(co) -- Task resumed