Lua with Neovim: Type Conversion — Automatic Coercion, Safe Defaults & Explicit Casts | Episode 28

Lua is dynamically typed and sometimes converts types automatically — but not always the way you expect. In this episode we cover explicit conversion with tonumber and tostring, how automatic coercion works (and when it doesn't), the safe default pattern for invalid input, and formatted output with string.format. Every keystroke is shown on screen with 3-second pauses so you can follow along at your own pace. Source code: https://github.com/GoCelesteAI/learn-lua-in-neovim What You'll Learn: - tonumber(value) — convert strings to numbers safely - tostring(value) — convert anything to a string - Automatic coercion — when Lua converts types for you - Coercion pitfalls — where automatic conversion fails - Safe default pattern — handling nil from tonumber - string.format — precise control over number and string output Timestamps: 0:00 Intro 0:12 Preview 0:44 Automatic Coercion 1:17 Running — coercion output 1:31 Coercion Failure (pcall) 3:03 Running — failure output 3:17 tonumber() 4:50 Safe Default Pattern (tonumber or 0) 6:25 Running — tonumber output 6:39 tostring() 8:09 string.format for Numbers 9:39 Running — final output 9:52 Review 10:07 Recap 10:39 Endscreen Key Takeaways: 1. tonumber returns a number or nil if conversion fails 2. tostring converts any value to its string representation 3. Lua auto-coerces strings to numbers in arithmetic 4. Coercion does not work with comparison operators 5. Always check tonumber results — nil means invalid input This is Episode 28 of the Learn Lua in Neovim series. New episodes cover metatables, OOP, and the Neovim Lua API — all coded inside Neovim. Taught by CelesteAI. Like & subscribe for more tutorials! #lua #neovim #programming #tutorial #beginners #learnlua #luaprogramming #neovimtutorial #luatonumber #luatostring #coding Tags lua, lua tutorial, learn lua, lua type conversion, lua tonumber, lua tostring, lua coercion, lua automatic coercion, lua string.format, lua safe defaults, lua type casting, lua dynamic typing, lua for beginners, neovim lua, neovim tutorial, learn lua in neovim, lua episode 28, programming tutorial, coding tutorial, beginner programming, lua 2026, neovim 2026, screenkey, code along, lua intermediate, lua types