What is a Ruby hash? A hash is a data structure used to store data in the form of UNIQUE key-value pairs. Unlike arrays, there are no numerical indexes, you access the hash values with keys… Read More

If you’re learning Ruby you may find the use of the “self” keyword very confusing. How does it work? What is self, exactly? It’s a Ruby keyword that gives you access… Read More

You may be learning Rails & you read that you have to create a “scaffold” to get your Rails application started. Easy! You can do this using the rails g scaffold command. But… Read More

Did you know that you can navigate your file system with Ruby? With the Ruby “Dir” class. You can list directory entries, change your current directory & even create new fold… Read More

How do you move from Java to Ruby? In this guide, you’ll learn what are the major differences between the two languages to help you make the jump. It’s great for the many people… Read More

What are helpers in Rails? A helper is a method that is (mostly) used in your Rails views to extract reusable code. Rails comes with a set of useful built-in helper methods. One of these bui… Read More

What does the word “yield” mean in Ruby? And what does it do exactly? Well… Yield is a keyword (meaning it’s a core part of the language) & it’s used insid… Read More

Ruby never stops improving! Version 2.7 is around the corner with new features & methods. It’s scheduled for release on December 25, 2019. Now, according to Matz… This is th… Read More

Many people are attracted to Ruby because Ruby on Rails makes building web applications faster. That’s fine. But then, when you find out how beautiful Ruby is, you fall in love with th… Read More

What are flash messages? A flash message is a way to communicate information with the users of your Rails application so they can know what happens as a result of their actions. Example mess… Read More

If you want to get the most performance out of your Ruby projects we have to explore fibers & how they work. Let’s start with a simple question… What are fibers? Fibers are… Read More

A queue is like a waiting list. Imagine you’re waiting in line to buy the latest Apple product, getting a movie ticket, or to pay for your groceries. These are queues! You can use queu… Read More

You’re writing a Ruby program & you want to ask the user a question… How do you go about that? Well, you can use the Ruby gets method. You call gets… Then your progra… Read More

What is a scope in Rails & why is it useful? Well… Scopes are custom queries that you define inside your Rails models with the scope method. Every scope takes two arguments: A nam… Read More

Learning Ruby can be overwhelming with all the bits & pieces you have to remember. That’s why I put together this syntax reference for you! It will help refresh your memory & q… Read More

What is a ternary operator in Ruby? A ternary operator is made of three parts, that’s where the word “ternary” comes from. These parts include a conditional statement &… Read More

Why do we need design patterns? The problem is that Rails architecture, Model-View-Controller, gives you a basic structure to put your code in. But this isn’t enough. Your views grow l… Read More

What are the best Ruby gems that you can use in your Rails projects? That’s what you’ll discover in this article! I’m going to give you 7 gems, but not the same old gems th… Read More

Keywords, like next & break are part of the Ruby programming language, so if you want a complete understanding of Ruby you need to know how these keywords work. What are they used for? W… Read More

How do we bring together multiple source code files into one? We require them. This tells Ruby to look for a file & run the code inside it. But sometimes we don’t need to load thes… Read More

You start building your new shiny web application in Ruby. And before you write any code… You want to see it load in your browser, even if just to see the default “welcome&rdquo&hell…Read More

Logging is the process of saving information about what your Ruby application is doing. It’s very helpful, both in development & production environments. Why? Because the whole poi… Read More

With the uniq method you can remove ALL the duplicate elements from an array. Let’s see how it works! If you have an array like this one: n = [1,1,1,2,3,4,5] Where the number 1 is du… Read More

What is infinity in Ruby? It’s something that has a starting point but no ending. In Ruby, we can express this concept of infinity with the Float::INFINITY constant. You may be wonderi… Read More

In Rails, you can query the database through your models to access your data. You can do this using ActiveRecord methods. Like where, find, or find_by. As a result you get: With find_by, a s… Read More

Combining multiple strings together is something that you have to do often in Ruby. But how can you do that? Well… There are two ways: Ruby string concatenation Ruby string interpolat… Read More

Let’s talk about Ruby’s gsub method. First, you’ll need a string to play with this method. Why? Because you use gsub on a string to replace parts of it. In fact: The &ldquo&hell…Read More

If you want to learn about instance variables, how they work & why they’re useful. You’re in the right place! First question… What’s an instance variable? In the… Read More

Let’s talk about the begin keyword in Ruby. What is it? First, you need to understand something. Your Ruby programs may trigger an error state at multiple points while they’re ru… Read More

What is Sequel? Sequel is a gem that allows you to access your database, no Rails required. You can connect to your database in different ways. Mostly two: By sending raw SQL commands By usi… Read More

What is a Ruby method? A method is made of lines of Ruby code grouped together with one specific goal. The goal can be to: GET information CHANGE or CREATE objects   Example 1: The size… Read More

Let’s talk about Rails parameters! Why are they useful? Users can send data to your web application in three different ways. These three ways are: Using a query parameter ("example.com… Read More

How can strings of characters exist in a world where computers only understand ones & zeros? Well… Just like we can map a domain name to an IP address. Or a barcode to a specific… Read More

I want to answer one simple question… What is FFI in Ruby? FFI stands for “Foreign Function Interface”. It’s a way to use functions defined in other programming lang… Read More

Ah, yes. The link_to method. One of the most common helper methods you’ll use in your Rails applications. But how does it work? If you came here to learn about link_to & the differ… Read More

Creating a temporary file gives you an empty file with a random name inside your O.S. (Operating System) temporary folder. This file gets deleted automatically. How can you do this in Ruby?… Read More

What is Cron? Cron is a job scheduling system available in Linux & MacOS operating systems. It can be used to run any program at any given time. This includes Ruby code! If there is a sp… Read More

What is Redis? Redis is a kind of in-memory database that has different kinds of data structures you can use. Like: Key / value storage Lists Sets It has nothing to do with your typical SQL… Read More

What is a data structure? A data structure is a specific way to organize & access data. Examples include: Arrays Binary trees Hashes Different data structures excel at different tasks. F… Read More

You can use the select method in Ruby to filter an array of objects. For example, you can find all the even numbers in a list. Without select that looks like this: even_numbers = [] [1,2,3,4… Read More

The ultimate goal of your Ruby on Rails application is to render a view. A view is what the user sees. It’s the culmination of all the work your app has to do, combining logic, data &a&hell…Read More

Scope is an important concept to understand for all Ruby developers. It’s the source of many error messages & confusion. What is scope? Scope refers to what variables are available… Read More

The normal flow of visiting a website is that you load a page & if you want to see new information you have to either reload the page to update it, or click a link to visit a different p… Read More

Did you know that the Ruby interpreter has lots of interesting & useful command-line options? Like: ruby -v Which gives you the Ruby version you are using right now. Or the -e flag which… Read More

How do you stop a Ruby program early? Normally a program will run until it’s done processing all the instructions. Or until it raises an exception that doesn’t get handled. But i… Read More

One way to learn new Ruby tricks, patterns & methods is to read code others have written. But where do you find interesting code worth reading? We have many open source projects, and cod… Read More

A Ruby class helps you define a blueprint for objects. Objects are the products of the class. So what is an object? An object is an individual “thing”, with its own identity &amp&hell…Read More

Rake is a popular task runner in Ruby. What is a task? Making a backup of your database Running your tests Gathering & reporting stats These are small tasks that without Rake would be sc… Read More

What is a boolean? A boolean is a value used in a logic statement to say if something is considered true or false. This can be used to make decisions. In Ruby we don’t have a Boolean c… Read More

I/O stands for Input/Output. By input we mean all the data & information that comes into something (computer, Ruby method, your brain). Examples of input: Keys your press on the keyboard… Read More

You’re going to be spending a lot of your time as a developer inside the editor, so it important to use an editor that you’re comfortable & productive with. In this article:… Read More

You can use a Ruby comment to add information to your code that may be helpful for you or other developers. The most common type of comment is the single-line comment. Here’s the synta… Read More

Looking for some new & interesting gems to try? Then have a look at dry-rb, a set of gems that bring solutions to common problems. Dry-rb is composed of over 18 Ruby gems that can work t… Read More

The initialize method is part of the object-creation process in Ruby & it allows you to set the initial values for an object. In other programming languages they call this a “const… Read More

Do you need to know math to become a good programmer? It depends! If you’re just going to be writing CRUD apps all day then you probably don’t need to know much math, if any. But… Read More

Did you know that you can control a web browser with Ruby? The Watir gem allows you to do this. And it comes with the full power of modern browsers: You can take a screenshot of the visible… Read More

Inheritance is a fundamental OOP feature that allows you to create a more specific & specialized version of a class. Here’s an example: Food -> Fruit -> Orange There’s… Read More

An environment variable is a key/value pair, it looks like this: KEY=VALUE We use these variables to share configuration between programs. Examples: Setting your default editor Telling Ruby… Read More

A matrix is a 2D (2-dimensional) array that can be used to store & work with spreadsheet-like data. They can be used for: Representing a board in a table game (chess, checkers, etc.) Sta… Read More

When you print a string or array you see its contents. Example: puts [1,2,3] 1 2 3 But when you print your own objects… You see this: #’… Read More

Many people forget that Ruby can do things that aren’t web applications. In this article, I want to show you how to build a command-line application to help remedy that. Here are some… Read More

If you work with any kind of images in your Ruby application there is a good chance that you’ll want to change them in one way or another. Like resizing them to save space & faster… Read More

If your Ruby application works with any kind of external API then you probably have faced the problem of slow tests & API rate limits. What is the solution? You could manually stub the H… Read More

REPL stands for Read-Eval-Print-Loop. It’s a program that allows you to type Ruby code & see the result directly. This is useful because you can quickly test how something works. F… Read More

Imagine a traffic light… It can be red, green or yellow. When it changes colors, the next color is based on the current one. Let’s say that this is the kind that makes a sound f… Read More

If you want to run an external command from Ruby… …like wkhtmltopdf to convert an HTML file into a PDF. There are a few Ruby methods you can use. Depending on the method you us… Read More

What is a heredoc? A heredoc is a way to define a multi-line string, while maintaining the original indentation & formatting. This is used to embed snippets of code, like SQL or HTML. He… Read More

Did you know that you can copy an object in Ruby? Not only that, but there are two different methods to do this! These methods are: dup clone We will explore the differences in a moment, but… Read More

Ruby’s performance has been improving a lot, version after version… and the Ruby development team is making every effort to make Ruby even faster! One of these efforts is the 3… Read More

You can give an alternative name to a Ruby method in two ways: alias (keyword) alias_method Because they do the same thing in slightly different ways this can be a confusing topic. Let&rsquo&hell…Read More

A new version of Ruby is coming with new features & performance improvements. Would you like to keep up with the changes? Let’s have a look! Endless Ranges Ruby 2.5 & older ver… Read More

ERB is a templating engine. A templating engine allows you to mix HTML & Ruby. This helps you generate your page dynamically using data from your database. ERB is Rails default engine fo… Read More

Let’s say that you have a class with instance variables & you want to expose them to the outside world… How? You have to define a method. Only methods can access instance va… Read More

Doing coding challenges is an excellent way to improve your Ruby & problem-solving skills. Why? Because you put all your focus on solving 1 specific problem. You don’t have to worr… Read More

Ruby has this defined? keyword that helps you check if a variable is defined or not. If the variable exists you’ll get its type: apple = 1 defined?(apple) # "local-variable" If it does… Read More

There are many ways to print something in Ruby. Here are the most useful: puts print p But how are these different? And when should you use one or the other? That’s what you’re g… Read More

What is a mock in RSpec? (Or a mock in general, because this isn’t a concept unique to RSpec.) A mock is an object used for testing. You use mocks to test the interaction between two o… Read More

CSV stands for “Comma-Separated Values”. It’s a common format for exporting & importing data. For example: You can export your Gmail contacts as a CSV file, and you can… Read More

Today you’ll learn about 4 Enumerable methods that will help you check a conditional statement against an array of elements, a hash, or any other objects that include the Enumerable mo… Read More

Let’s talk about the grep method. What can this method do for you? You can use Grep to filter enumerable objects, like Arrays & Ranges. “But select already does that!”… Read More

Ruby on Rails is an open-source web application framework. A framework is a collection of code, tools & utilities that give you a specific structure to work with. This structure makes yo… Read More

Map is a Ruby method that you can use with Arrays, Hashes & Ranges. The main use for map is to TRANSFORM data. For example: Given an array of strings, you could go over every string &amp&hell…Read More

What does public, private & protected mean in Ruby? These 3 methods control the public interface of your class. They control WHO can call these methods. By default all your methods are p… Read More

In Object-Oriented Programming, there are two ways for classes to work together. They are: Inheritance Composition With inheritance, you create class hierarchies, where a parent class shares… Read More

A Ruby gem packages together Ruby code in a way that is easy to share with others. Gems solve mostly two problems: A common format for sharing libraries & tools in Ruby A way to describe… Read More

If you would like to use string methods (like gsub) but you’re working with an integer… What can you do? Use a conversion method! For example: You can convert the Integer 1 to t… Read More

What does the super keyword do in Ruby? It calls a method on the parent class with the same name as the method that calls super. For example: If you call a method named i_like_chocolate, and… Read More

Would you like to know what goes on behind the scenes of Rails, Sinatra, and other Ruby web frameworks? Then you’re in the right place. Because today we are going to talk about Rack! R… Read More

N-Queens is an interesting coding challenge where you have to place N queens on a N * N board. It looks like this: A queen can move in all directions: Vertical Horizontal Diagonal The soluti… Read More

A set is a class that can hold items in a similar way that an array does… …but with some special attributes. With the main benefit being this: All the items in a set are guaran… Read More

If you’d like to get information from a website, or if you’d like to submit forms, upload files… …you’ll need to send an HTTP request & then process the r… Read More

Would you like to learn how to write tests for your Ruby applications using RSpec? Then you’re in the right place! In this tutorial I’ll show you how to do that. Why Should You W… Read More

Ruby has a lot of interesting operators, like the spaceship operator (), the modulo assignment operator (%=), and of course the regular operators like greater than (>) & not equals (!… Read More

I got an email asking for my opinion about when to use keyword arguments. I thought I’d expand my answer into a full article about method arguments so everyone can benefit! Ruby is ver… Read More

Following my last article, why do we use nil, I thought it’d be a good idea to ask this question for other things that we take for granted. Like… Why do we use classes instead o… Read More

I was having a chat with a friend about a piece of Ruby code & the topic of return values came up… …and of course, nil is always part of that conversation. Later that day… Read More

Have you ever wanted to create a class that can only have one instance? No? Me neither. But that’s exactly what the singleton pattern is. Some people even call this an anti-pattern! Le… Read More

A very important topic in object-oriented design is cohesion & coupling. Cohesion is about the relationship between all the methods inside a class. Are they using the same set of instanc… Read More

Let’s talk about the strategy design pattern! This design pattern helps you change the main algorithm inside a method. You do this by passing in a class that implements this algorithm… Read More

The decorator design pattern… What is it, and how can you use this pattern in your Ruby projects? The decorator design pattern helps you enhance an object by adding new capabilities t… Read More