Education Ecosystem Blog

 
In Ruby, as in other programming languages, an array is a list of items with an order within your code. Each item has its position in this list and acts as a variable: you can see which object points to a given position, and you can make it point to a different object.
You can create an array using square brackets, for example:

 ['Cat', 'Dog', 'Bird'].

There is no need to create an array with all its content at once. It can be manipulated even after its creation.

After storing this initial data, the array can be changed or have its values checked. To retrieve the values stored in it, you must specify which value you want. The items in the array are numbered from left to right, starting from the first one, and this item is called the index of the array.
 

How to check if a value exists in an array in Ruby

The main method to perform this operation is to use the .include? method.

 [  'Cat'  ,  'Dog'  ,  'Bird'  ] .include? Dog

true

As the answer, you will have “true” or “false.” If you are using Ruby on Rails, there are several other ways to do this, and we’ll show you one now.

How to check if a value exists in an Array in Ruby on Rails

There is a method in? at the ActiveSupport that exists in Rails since version 3.1. So you can run this query with the code below:

require 'active_support'

'Unicorn'.in? (['Cat ',' Dog ',' Bird ']) # => false

Do you know other ways to do this type of check? Share it in the comments section at the end of this article!

If you want to explore other issues, can check our videos about Ruby. Below are some examples:

• Online game store

• Working on a start up

 
You can also subscribe to some channels that broadcasts in Ruby, such as the following:

samaaron

 JD-P

Another cool way to find out interesting things about Ruby is to access our project page!