---
title: Factorial with Ruby
slug: factorial-with-ruby
published_at: 2022-09-09 12:00:12 +0000
updated_at: 2026-03-04 20:13:23 +0000
summary: 
description: Factorial with Ruby
tags: [cjav_dev, web development tutorials, web development for beginners, vim, ruby, rails, ruby on rails, factorial, learn to code, programming tutorial, programming language, programming language for beginners]
views: 237
author: CJ Avilla
url: https://www.cjav.dev/videos/factorial-with-ruby
youtube_url: https://www.youtube.com/watch?v=D2LdKxE3wt4
youtube_id: D2LdKxE3wt4
embed_url: https://www.youtube.com/embed/D2LdKxE3wt4
thumbnail_url: https://i.ytimg.com/vi/D2LdKxE3wt4/hqdefault.jpg
type: video
---

# Factorial with Ruby

*Published: September 09, 2022*
*Views: 237*

## Watch

[Watch on YouTube](https://www.youtube.com/watch?v=D2LdKxE3wt4)

[![Factorial with Ruby](https://i.ytimg.com/vi/D2LdKxE3wt4/hqdefault.jpg)](https://www.youtube.com/watch?v=D2LdKxE3wt4)

## Description

Factorial with Ruby

## Transcript

let's implement a factorial function in ruby so we'll define a function called factorial and it's going to take in some number and we're going to call factorial with some number let's say 3 to start and the factorial is 3 times two times one so factorial is n times n minus one until we get all the way down to zero and so we're gonna print this out and to start it's gonna not print anything so we'll say ruby factorial we get nothing back that's because we haven't implemented our function yet so here github copilot is making it too easy for us so that is going to be the implementation of our factorial but let's show our work so if we're inside of here let's print out okay if we're at the very last number then we want to say that we're going to multiply by 1 and that's going to give us how much it equals otherwise let's print out the number n times so that we can see as we go so 3 times 2 times 1 times 0 okay we could also make this 1 here and we would get the same so 3 times 2 times 1 is equal to 6. let's change our number to let's say 5 and now if we run this again now we have five times four times three times two times one the factorial of five is one hundred twenty so this is one way that you might implement the factorial function this call here is called a recursive call and that's because we're calling the factorial method inside of its self so while we're executing factorial we're calling factorial again

---

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