Ruby - Iterators (each) 2020

In Ruby, arrays and hashes are collections. Iterators are nothing but methods supported by collections. Iterators return all the elements of a collection, one after another.In this chapter, we introduce one of the iterators, each.

The each iterator returns all the elements of an array or a hash, and the syntax looks like this:

collection.each do |variable|
   ...
end

Example:/p>

#!/usr/bin/env ruby
# array.rb
ary = ['a', 'b', 'c']
ary.each do |i|
   puts i
end

Output:

$ ./array.rb
a
b
c

We always associate the each iterator with a block. It returns each value of the array, one by one, to the block.

Ruby on Rails

• Ruby On Rails Home
• Ruby - Input/Output, Objects, Load
• Ruby - Condition (if), Operators (comparison/logical) & case statement
• Ruby - loop, while, until, for, each, (..)
• Ruby - Functions
• Ruby - Exceptions (raise/rescue)
• Ruby - Strings (single quote vs double quote, multiline string - EOM, concatenation, substring, include, index, strip, justification, chop, chomp, split)
• Ruby - Class and Instance Variables
• Ruby - Class and Instance Variables II
• Ruby - Modules
• Ruby - Iterator : each
• Ruby - Symbols (:)
• Ruby - Hashes (aka associative arrays, maps, or dictionaries)
• Ruby - Arrays
• Ruby - Enumerables
• Ruby - Filess
• Ruby - code blocks and yield
• Rails - Embedded Ruby (ERb) and Rails html
• Rails - Partial template
• Rails - HTML Helpers (link_to, imag_tag, and form_for)
• Layouts and Rendering I - yield, content_for, content_for?
• Layouts and Rendering II - asset tag helpers, stylesheet_link_tag, javascript_include_tag
• Rails Project
• Rails - Hello World
• Rails - MVC and ActionController
• Rails - Parameters (hash, array, JSON, routing, and strong parameter)
• Filters and controller actions - before_action, skip_before_action
• The simplest app - Rails default page on a Shared Host
• Redmine Install on a Shared Host
• Git and BitBucket
• Deploying Rails 4 to Heroku
• Scaffold: A quickest way of building a blog with posts and comments
• Databases and migration
• Active Record
• Microblog 1
• Microblog 2
• Microblog 3 (Users resource)
• Microblog 4 (Microposts resource I)
• Microblog 5 (Microposts resource II)
• Simple_app I - rails html pages
• Simple_app II - TDD (Home/Help page)
• Simple_app III - TDD (About page)
• Simple_app IV - TDD (Dynamic Pages)
• Simple_app V - TDD (Dynamic Pages - Embedded Ruby)
• Simple_app VI - TDD (Dynamic Pages - Embedded Ruby, Layouts)
• App : Facebook and Twitter Authentication using Omniauth oauth2
• Authentication and sending confirmation email using Devise
• Adding custom fields to Devise User model and Customization
• Devise Customization 2. views/users
• Rails Heroku Deploy - Authentication and sending confirmation email using Devise
• Deploying a Rails 4 app on CentOS 7 production server with Apache and Passenger I
• Deploying a Rails 4 app on CentOS 7 production server with Apache and Passenger II
• OOPS! Deploying a Rails 4 app on CentOS 7 production server with Apache and Passenger (Trouble shooting)