Diagnostic Week 2 and 3

This exercise is intended to help you assess your progress with the concepts and techniques we’ve covered during the week.

For these questions, write a short snippet of code that meets the requirement. In cases where the question mentions a “given” data value, use the variable given to refer to it (instead of re-writing the information).

Use single (`) and triple backticks (```) to container code snippets.



Define a class called PizzaOven which has a method cook_pizza which returns the string "mmm 'za".

Class PizzaOven

    def initialize
      	@cook_pizza = cook_pizza
    end

    def cook_pizza
      "mmm 'za"
    end
end



Define a class called Student which is instantiated with a “name” value and which has a method name that returns this value

  class Student
    def initialize
      @name = name
      end

      def name
        @name
      end
  end


Given an array of the numbers [1,2,3,4,5], find the sum of the doubles of all the numbers

  numbers = [1,2,3,4,5]

    total = numbers.map do |x| 
        x * 2
    end

    total.reduce(:+)

Give the command to create a new Git repository in a directory on your machine

    git init or "Get in it"

Pizza

Given a hypothetical Pizza class which has an instance method is_tasty? that always returns true, write a simple Minitest test that tests this behavior.


    def test_tasty_returns_true

        pizza = Pizza.new
      
        assert pizza.is_tasty?
    end


Suppose the Pizza class also has a method style which randomly returns one of: "supreme", "mediterranean", or "cheese". Write a test that confirms that the returned pizza style is within this list.

      def test_returns_random_style_of_pizza_from_list

        pizza = Pizza.new

        pizza_type = ["supreme", "mediterranean", "cheese"]

        assert_equal ["supreme", "mediterranean", "cheese"], pizza.random_pizza_choice(array)
        
       end

Give the Git commands needed to stage and then commit a set of changes to a file

      git add . then git commit -m "boom" then git push

Student

Define a Student class which, when created, has an attitude attribute. attitude should start out with the value “cheerful”, and the Student class should provide a “reader” method that allows us to access the value of its attitude.

Additionally, add an assign_homework method to Student. When assigned_homework is invoked, if the student’s attitude is "cheerful", it should become "dubious". If the value is currently "dubious" it should become "perturbed". If the value is currently "perturbed", it should become "dazed". Assigning homework to a "dazed" student has no effect.

Building on the Student class from the previous example, update the assign_homework method to accept an argument. The argument will be a String containing a short description of the assignment. For example we might use it like this:

s = Student.new
s.assign_homework("Write a linked list")
Then, add an assignments method to Student. assignments should return a list of all the assignments that have been given, separated by a comma and a space. For example:

s = Student.new
s.attitude
=> "cheerful"
s.assign_homework("write a linked list")
s.attitude
=> "dubious"
s.assign_homework("write a BST")
s.attitude
=> "perturbed"
s.assignments
=> "write a linked list, write a BST"
Given an array of 3 Student instances, generate a new string of all of their assignments
For example:

s1 = Student.new
s2 = Student.new
s3 = Student.new

s1.assign_homework("linked list")
s1.assign_homework("sorting algos")

s2.assign_homework("write a c compiler")
s2.assign_homework("write a pacman game")

s3.assign_homework("headcount")
s3.assign_homework("sales engine")

students = [s1,s2,s3]

# YOUR CODE HERE

class Student

   attr_reader :attitude

   def initialize(attitude= "cheerful")
     @attitude = attitude
     @homework = 0
     @assignments = ""
   end

   def assign_homework(assignment)
    @homework += 1
    @assignments << assignment
    end

  def attitude_changer
    if @homework == 1
      @attitude = "dubious"
    if @homework == 2
      @attitude = "perturbed"
    if @homework >= 3
      @attitude = "dazed"
  end
 end
 

=> "linked list, sorting algos, write a c compiler, write a pacman game, headcount, sales engine"
What does the following code output?
def print_variables(x)
  puts "x: #{x}"
  puts "b: #{b}"
end

def b
  12
end

a = 4
print_variables(a)

x: 4
b: 12


Working with files: given a text file located at "~/Documents/pizza.txt", write code to read the file from the filesystem and print each line one at a time.

Writing Files: given a text file located at "~/Documents/pizza.txt", write code to read the file from the filesystem, then write a new file at "~/Documents/line_count.txt" containing the number of lines in the original file.

Imagine a simple ruby class designed to represent a Corgi dog. Write a test for each of the following features:

A Corgi can be created with no arguments
A Corgi can be assigned a name
A Corgi can be asked for its name
A Corgi can be asked for its posture, which should default to “standing”
A Corgi can be asked to lie down, which should change its posture to “laying”


  def test_corgi_can_be_made_no_arguments
    corgi = Corgi.new

    assert_instance_of Corgi
  end

  def test_corgi_can_be_named
    corgi = Corgi.new

    assert_equal "Joe", corgi.name
  end

  def test_a_corgi_can_be_asked_for_its_name
    corgi = Corgi.new

    assert true, corgi.ask_corgi_name?
  end

  def test_a_corgi_can_be_asked_for_its_posture
    corgi = Corgi.new

    assert_equal "standing", corgi.posture(position)
  end

  def test_corgi_can_be_asked_to_lie_down
    corgi = Corgi.new

    corgi.lie_down

    assert_equal "laying", corgi.posture(position)
  end