Lua Introduction

Lua is a lightweight, fast scripting language designed for embedding. It is one of the fastest scripting languages in the world — often faster than Python, Perl, and Ruby for comparable tasks.

Lua was created in 1993 at the Pontifical Catholic University of Rio de Janeiro, Brazil. Its name means "Moon" in Portuguese. Despite its small size (~300KB for the entire interpreter), Lua is used in production at some of the largest software companies in the world.

Where Lua is used

Why Lua?

• Tiny footprint — the entire interpreter compiles to ~300KB
• Very fast — consistently one of the fastest scripting languages
• Easy to embed — designed from the start to be called from C/C++
• Portable — runs on anything from microcontrollers to supercomputers
• Simple syntax — can be learned in a day

Hello World

print("Hello, Nepal!")

lua hello.lua    # run with Lua interpreter

Variables and Types

-- Lua has 8 types: nil, boolean, number, string, function, table, userdata, thread
local name = "Sita"        -- string
local age = 21             -- number (all numbers are floats in Lua 5.3+)
local active = true        -- boolean
local nothing = nil        -- nil (like null/undefined)

-- Strings
local greeting = "Hello, " .. name .. "!"   -- concatenation with ..
print(#greeting)          -- 13 (string length with #)
print(string.upper(name)) -- "SITA"
print(string.format("Age: %d", age))

Comments

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What you will learn