therod

Ruby Cheatsheet

Basic Math Operations

5.4 - 2.2 # Subtraction
4 * 72 # Multiplication
7 / 3.5 # Division
3 ** 7  # Exponentiation

therod

class Person
  attr_accessor :first_name, :last_name, :birth_year, :car_registration

  def initialize(first_name, last_name, birth_year, car_registration)
    @first_name = PersonDataChecker.check_name(first_name)
    @last_name = PersonDataChecker.check_name(last_name)
    @birth_year = PersonDataChecker.check_birth_year(birth_year)
    @car_registration = PersonDataChecker.check_car_registration(car_registration)
  end
end

therod

! Disable everything but the search & video player on YouTube.
www.youtube.com###primary > .ytd-two-column-browse-results-renderer.style-scope
www.youtube.com###secondary
www.youtube.com###guide-inner-content
www.youtube.com##ytd-mini-guide-renderer
www.youtube.com##ytd-watch-next-secondary-results-renderer

therod

Smalltalk Best Practice Patterns in Ruby

1 – INTRODUCTION

• We aren’t always good at guessing where responsibilities should go. Coding is where our design guesses are tested. Being prepared to be flexible about making design changes during coding results in programs that get better and better over time.

• If you’re programming along, doing nicely, and all of a sudden your program gets balky, makes things hard for you, it’s talking. It’s telling you there is something important missing.

• Some of the biggest improvements come from figuring out how to eliminate:

• Duplicate code (even little bits of it)

therod

#!/bin/bash
## Remove all local timemachine backups

for i in $(tmutil listlocalsnapshotdates / | awk '{print $1}' | sed -n '1!p' | xargs echo); do tmutil deletelocalsnapshots $i; done

therod

mentors = ["Hans", "Ruedi"].shuffle
attendees = ["Klara", "Kevin", "Mike", "Sandro", "Sandy", "Silvan", "Lala"].shuffle
number_of_groups = (attendees.count / mentors.count)

groups = attendees.each_slice(number_of_groups).to_a

mentors.each_with_index do |mentor, index|
  puts "Group #{index + 1}: #{mentor}"
  puts "===================="
  puts groups.shift

therod

require 'pry'
keys = `aws s3api list-objects --bucket master21 --query 'Contents[].{Key: Key}' --output text | grep -v 'folder'`

keys = keys.split("\n")

keys.each do |key|
  system("aws s3api put-object-acl --acl bucket-owner-full-control --bucket master21 --key '#{key}'")
end

therod

require 'open-uri'
require 'prawn'

class OrangeTree

  def initialize
    @height = 0
    @orange_count = 0
    @fruit = 0
    @age = 0

therod

puts "Ha! Did you really think I would give away the solution that easily?"
puts "Try again!"

therod

class OrangeTree
  def initialize
    @height = 0
    @age = 0
    @oranges = 0
    @alive = true
  end

  def one_year_passes
    @alive = false if @height > 10 && rand(2) == 1