Skip to main content

Ruby – Difference between Require and Include

Ruby – Difference between Require and Include ?


While coding with Ruby or Ruby on Rails, you might have came across Require and Include. There are quite a few differences between Require and Include.

First of all let us see, what Require does in Ruby.
1. REQUIRE

Syntax:

require(name)

Returns: boolean (true/false)

Action
The name which is passed as parameter to the require, ruby will try to find the source file with that name in your load path.

What is load path?

The load path is the path from where library files for your program are loaded. You can see what is the load path for your programs by the following command.

> $load_path

This will list the load path i.e. locations from where library files are loaded.

If name which is passed as argument includes extension .rb then ruby will try to find the file with the same name and extension in the load path, otherwise i.e. If you do not provide the extension for the name then ruby will try to find the file with same name with .rb as it's extension. The name nay be given for the .dll, .so files.

Require also takes care of whether your files are previously loaded or not. Optimization is done based on this information.

You can try using require until you get comfortable with it.
2. INCLUDE

Syntax: include module_name

Action:
The include is another important feature provided by Ruby just to ensure DRY principle.

What is DRY?

If you don't know what is DRY, they you should start learning Ruby. The Don't Repeat Yourself (DRY) principle is provided by the ruby just to avoid avoid code duplicity, in fact any kind of duplicity.

Suppose if you have some methods that you need to have in two different classes. Then you don't have to write them in both the classes. Instead what you can do is, define it in module. And then include this module in other classes.

module RubyModule
 def put_message
    puts "Ruby in Rails is Amazing"
 end
end

Then, what you can do with this module is you can include it in any class where you would want the method put_message

For example,

class Person
include RubyModule
end

Then, ultimately class person gets equipped with the method that are include in the module named RubyModule.
These are the basic differences between use of Ruby Require and Ruby Include.

Comments

Post a Comment

Popular posts from this blog

Error malloc(): memory corruption nginx with passenger?

Error malloc(): memory corruption nginx with passenger Passenger issue resolving steps :  sudo gem uninstall passenger(uninstall all passenger) sudo gem install passenger sudo passenger-install-nginx-module --auto --auto-download --prefix=/opt/nginx --extra-configure-flags=none Update nginx config file with new passenger version and restart the nginx
1 comment
Read more

Lazy loading in rails – Rails Feature

 Lazy loading in rails – Rails Feature ? Lazy loading in rails is the amazing feature provided with rails. In console you might have tried to examine how lazy loading in rails actually works. In this tutorial, we will learn about this Rails - Lazy loading feature with examples. What exactly is Lazy Loading? As the name suggests the data is loaded in lazy manner (Really!) i.e. Your database is queried only when data from the database is required for some kind of manipulation in code. You will get more of this after you read how-to of lazy loading below. How lazy loading works: Whenever you try to get some data from database, For example, users is the database table that you have. And you are querying database to get users having age less than 20. Then, you will write code like, result = User.where("age < 20") when above statement is executed, your database is not queries yet(because the resultant data is not required yet). When you execute following code, records = resu...
Post a Comment
Read more

Rails Migration Difference between Text and String

Rails Migration Difference between Text and String ? While working with Rails Migration Difference between Text and String is important to be known to every developer. Columns and their data types are finalized while deciding Table structure. This tutorial will help understand difference between String and Text column type and illustrate how to write Rails Migration implementing the same. You might want to read about database.yml files for specifying database configuration for Rails Application. 1. Concepts When String or Text data type is required?     Whenever you require your column to store information which is lengthy in size (Many characters), you need to consider String or Text data type for the column.     Both of them let you store Many(How Many - will see later) characters Difference between String and Text Considering MySQL database Feature     String     Text Length     1 to 255     ...
Post a Comment
Read more