The Ruby programming

Languague

Ruby is a powerful, flexible programming language you can use in web/Internet development, to process text, to create games, and as part of the popular Ruby on Rails web framework.

Ruby is:

High-level: meaning reading and writing Ruby is really easy—it looks a lot like regular English.

Read this in loud voice:

5.times { print "Apprentice!" }

 

exit unless "restaurant".include? "aura"

 

['toast', 'cheese', 'wine'].each { |food| print( food.capitalize ) }

Interpreted: meaning you don't need a compiler to write and run Ruby.

 

Object-oriented: meaning it allows users to manipulate data structures called objects in order to build and execute programs. All you need to know (for now) is that (almost) everything in Ruby is an object.

Easy to use: Ruby was designed by Yukihiro Matsumoto (often just called "Matz") in 1995. Matz set out to design a language that emphasized human needs over those of the computer, which is why Ruby is so easy to pick up.

Yukihiro Matsumoto a.k.a. Matz14 April 1965, Japan

string = "This is a string"
fixnum = 1
float = 1.0
regex = /d+/

array = Array.new
array[0] = 'element 1'
array[1] = 'element 2'

hash = Hash.new
hash[:key_a] = 1
hash[:key_b] = 2

Data Types

Syntax

class Badgers
  attr_accessor :count

  def initialize
    @count = 1
  end

  def count_badgers
    puts 'Counting badgers...'
    (1..@count).each do |n|
      if n % 5 == 0
        puts "Mushroom mushroom!"
      else
        puts "#{n} Badger"
      end
    end
  end
end

b = Badgers.new

puts "Current number of badgers: #{b.count}"
b.count_badgers
puts

b.count = 10
puts "Current number of badgers: #{b.count}"
b.count_badgers
require 'awesome_print'

ap('This is a string'.reverse)
ap(1.odd?)
ap(1.25.denominator)
ap(/A\d+/.match 'A01164096')
ap([1, 2, 3, 4, 5].shuffle)
ap({key_a: 1, key_b: 2}.merge({key_b: 2.5, key_c: 3}))

Everything is an Object

Return an array containing the numbers from 1 to N, where N is the parametered value. N will never be less than 1.

Replace certain values however if any of the following conditions are met:

  • If the value is a multiple of 3: use the value 'Fizz' instead
  • If the value is a multiple of 5: use the value 'Buzz' instead
  • If the value is a multiple of 3 & 5: use the value 'FizzBuzz' instead

FizzBuzz

15 mins ⏲

Real world Ruby

HTTP

Simple Web Service

Twitter API

Ruby 101

By Carlos Contreiras

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Ruby 101

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