DEV Community

AB
AB

Posted on

Ruby basics cheat sheet

My Ruby Learning Journey: From while Loops to a Cheat Sheet

Learning to code can feel like you're constantly collecting a mountain of notes and code snippets. Recently, I was struggling to nail down Ruby's basic control flow, especially with while loops. The syntax seemed simple, but keeping track of the loop condition and the iterator was a challenge.

After working through it, I realized a lot of my frustration came from managing too many moving parts. A while loop requires you to declare an iterator, set a condition, and manually increment the iterator inside the loop.

I was surprised to discover how much cleaner a for loop is for this exact task. The syntax for i in 1..5 handles everything—the starting value, the ending value, and the incrementing—all in one line. This simple change made me appreciate how different loops are designed for different tasks.

This experience inspired me to collect all the core Ruby concepts I've been learning into a single, clean reference guide. I wanted something I could look at quickly to remember a method or its syntax.

Here's the cheat sheet I put together, covering the fundamentals that every Ruby developer should know.


The Ruby Fundamentals

1. Core Data Types

Topic Key Methods & Concepts Example
Strings length, count, upcase, capitalize, gsub "Hello".length => 5
Integers & Floats Division behavior, .odd?/.even?, .to_f 10 / 3 => 3 <br>10 / 3.0 => 3.333...

2. Collections

Topic Key Methods & Concepts Example
Arrays push (<<), pop, delete, delete_at [1, 2].push(3) => [1, 2, 3]
Hashes Keys & Values, [] for access, fetch h = {:a => 1}; h[:a] => 1

3. Control Flow

Topic Key Methods & Concepts Example
Conditionals if, unless if x > 0<br>unless x <= 0
Loops each, select, reject, while, for [1,2,3].each {..}<br>for i in 1..5

I found that going back to these basics and creating my own reference was incredibly helpful. It reinforces the concepts in a way that just reading a tutorial can't.

If you're interested in an even more dynamic version of this, I built an interactive web app that lets you search and copy code examples instantly. You can check out the full code in a previous post here.

I hope this helps you on your own Ruby journey!

Top comments (0)