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Module 1 Week 2 Diagnostic

When complete, fill out this form.

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).

1. Define a class called PizzaOven which has a method cook_pizza which returns the string "mmm 'za"
class PizzaOven
  def cook_pizza
    "mmm 'za"
  end
end
2. Define a class called Student which is instantiated with a "name" value and which has a method name that returns this value
class Student
  attr_reader :name
  def initialize(name)
    @name = name
  end
3. Given an array of the numbers [1,2,3,4,5], find the sum of the doubles of all the numbers
given.map {|num| num*2}.inject(:+)
4. Give the command to create a new Git repository in a directory on your machine
git init
5. Testing and 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.

pizza = Pizza.new
assert pizza.is_tasty?, "For some reason, this pizza is not tasty!"

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.

assert ["supreme","mediterranean","cheese"].include?(pizza.style)
6. Give the Git commands needed to stage and then commit a set of changes to a file
git add filename
git commit -m "Message of the updates made to the file"
7. More Objects

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.

class Student
  attr_reader :attitude
  def initialize(attitude="cheerful")
    @attitude = attitude
  end
  def assign_homework
    @attitude = "dubious" if @attitude == "cheerful"
    @attitude = "perturbed" if @attitude == "dubious"
    @attitude = "dazed" if @attitude == "perturbed"
  end
end
8. Adding to Students

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.

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:

class Student
  attr_reader :attitude
  def initialize(attitude="cheerful")
    @attitude = attitude
    @list_of_assignments = String.new
  end
  def assign_homework(assignment)
    if @attitude == "cheerful"
      @attitude = "dubious"
    elsif @attitude == "dubious"
      @attitude = "perturbed"
    elsif @attitude == "perturbed"
      @attitude = "dazed"
    end
    @assignment = assignment
  end
  def assignments
    if @list_of_assignments.empty?
      @list_of_assignments = @assignment
    else
      @list_of_assignments += ", #{@assignment}"
    end
    @list_of_assignments
  end
end
9. Inheritance

Create a new class SurlyStudent which inherits from the Student class above. However, whenever you ask a SurlyStudent for their attitude, they always respond with "disgruntled"

class SurlyStudent < Student
  def initialize
    @attitude = "disgruntled"
    @list_of_assignments = String.new
  end
  def assign_homework(assignment)
    @attitude = "disgruntled"
    assignments(assignment)
  end
end
10. Given an array of 3 Student instances, generate a new string of all of their assignments
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]

students.map {|student| student.assignments}.join
=> "linked list, sorting algos, write a c compiler, write a pacman game, headcount, sales engine"
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