includes vs. include?: The common misunderstanding


In the world of Ruby on Rails and Ruby, two deceptively similar methods, includes and include?, have entirely different roles. This blog post aims to shed light on their differences with concise examples to help you optimize your code effectively.

Optimizing Queries with includes:

includes is a powerful method in Ruby on Rails. Its primary role is to enhance database queries by eagerly loading associations, minimizing N+1 query problems. Let’s dive right into an example:

@articles = Article.includes(:comments)

In this instance, we fetch articles and their comments efficiently, ensuring all comments are loaded in a single query. The result? Improved performance.

Best Use: When you need to reduce database queries and enhance data retrieval in Rails.

Checking Element Presence with include?:

On the other hand, include? is a core Ruby method that verifies if a particular element exists in an array. It’s not Rails-specific, but it’s invaluable. Here’s how it operates:

if my_array.include?(my_element)
  # Implement specific actions if the element is present in the array

This code checks if my_element is within my_array before executing any actions.

Best Use: When you want to confirm an element’s presence in an array, enumerable, or collection.

In Summary:

  • includes in Rails optimizes database queries by eagerly loading associations.
  • include? is a core Ruby method for verifying element presence in arrays or collections.

Related Post