Lesson 37 of 55
9 mins readPython Prototype-Based OOP & Class Tables
In Plain English
Lua achieves object-oriented programming through prototype tables. A class is a table that serves as a prototype for instances using `setmetatable(instance, { __index = Class })`.
Deep Dive: How It Works
Prototype Pattern: Objects delegate missing method calls to their class table.
Class Table Setup: `Account = {}; Account.__index = Account`.
Instance Creation: `setmetatable(new_table, Account)` gives `new_table` access to all methods in `Account`.
Core Rules to Remember
Prototype OOP: Class methods are defined on a prototype table and inherited via `__index`.
Lightweight Objects: Instances are simple tables storing only their own field values.
Live Interactive Example
Hit Run Code to see it liveSimple Prototype Class in Lua
Python 3.12
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Output Console
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How it works: g1 inherited say_hi from the Greeter class prototype.
Your Turn: Micro Challenge
No pressure! Edit the starter code below and test your solution with instant feedback.
Micro Exercise
Create Point Prototype Class
- Define `local Point = {} Point.__index = Point`.
- Add `function Point.get_x(self) return self.x end`.
- Create `local p = { x = 42 }` with metatable `Point` and print `"X: " .. p:get_x()`.
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Sandbox Output
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