Mod 1 - Week 4 diagnostic

Week 4 Diagnostic

1. Give one difference between Modules and Classes.

Instances are made of classes while modules dont do instances, they are like libraries full of constants.

#classes have state. modules are stateless.

2. Defining Modules

First, create a module Doughy which defines a method has_carbs? that always returns true. Then, given the following Pizza class, update Pizza to use your new Doughy module to gain the defined has_carbs? behavior.

module Doughy
  def has_carbs?
    true
  end
end 

class Pizza
  include 'Doughy'
  def tasty?
    true
  end
end


3. What are two benefits modules provide us in Ruby? Elaborate on each.

modules have a namespace of methods and constants that dont interact with other things.
modules have mixins which allow multiple inheritence for classes

4. What values in Ruby evaluate as “falsy”?

false
nil

5. Give 3 examples of “truthy” values in Ruby.

true
6
"hello"

6. List 3 HTTP Verbs

GET, POST, ...
#DELETE, PUT

7. HTTP Parsing: given the following HTTP Request, identify the following:

HTTP Verb: POST
Request Path: /students
Query Parameters: ?name=horace


POST /students?name=horace HTTP/1.1
Host: 127.0.0.1:9292
Connection: keep-alive
Cache-Control: max-age=0
Accept: text/html
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8
What is the full request URL?

http://127.0.0.1:9292/students?name=horace

8. Git and Branches: give a git command to accomplish each of the following:

Switch to an existing branch iteration-1: 
git checkout iteration-1

Create a new branch iteration-2: 
git branch -add iteration-2
#git checkout -b iteration -2

Push a branch iteration-2 to a remote origin: 
git push origin interation-2

Merge a branch iteration-1 into a branch master (assume you are not on master to begin with): 
git checkout master
git merge iteration-1

9. Load Paths and Requires

Given a project with the following directory structure, give 2 ways that we could require file_one from file_two.

. <you are here>
├── lib
│  │── file_one.rb
│  └── file_two.rb

require './lib/file_one
require_relative './file_one

10. Refactoring: given the following snippet of code, show 2 refactorings you might make to improve the design of this code.

class Encryptor
  def date_offset
    date = Time.now.strftime("%d%m%y").to_i
    date_squared = date ** 2
    last_four_digits = date_squared.to_s[-4..-1]
    [last_four_digits[-4].to_i,
    last_four_digits[-3].to_i,
    last_four_digits[-2].to_i,
    last_four_digits[-1].to_i]
  end
end

Encryptor.new.date_offset

-------------
class Encryptor
  def date_offset
    date = Time.now.strftime("%d%m%y").to_i
    date_squared = date ** 2
    lfd = LastFourDigits.new(date_squared)
    lfd.last_four
  end
end

class LastFourDigits
  def initialize(number)
    @number = number
  end

  def last_four
    @new_num = @number.to_s[-4..-1]
    to_array
  end

  def to_array
    @new_num.chars
  end
end

puts Encryptor.new.date_offset