Checkpoint 04

Instructions

1. Fork this repo
2. Clone your fork
3. Fill in your answers by writing in the appropriate area or, for multiple-choice questions, placing an 'x' in the square brackets
4. Add/Commit/Push your changes to Github
5. Open a pull request

For questions 1-4, you must test your code before filling in an answer. You can do this by creating and running your own app.rb file.

Only place your answer between the backticks provided for you throughout the checkpoint.

Ruby Basics & Enumerables

Question 1

Define a method called offer_rose, which should take one argument named person (String).

When called the method should print "Would you take this rose, person, in exchange for giving an old beggar woman shelter from the bitter cold?" to the Terminal.

Demonstrate calling the method, passing in "young prince" as the argument.

# Your code goes here...

Question 2

Assume the following hash...

town = {
  residents: ["Maurice", "Belle", "Gaston"],
  castle: {
    num_rooms: 47,
    residents: "Robby Benson",
    guests: []
  }
}

Using Ruby...

• Remove "Belle" from residents
• Add "Belle" to the guests array

# Your code goes here...

Question 3

Assume you have an array of strings representing friends' names...

friends = ["Chip Potts", "Cogsworth", "Lumière", "Mrs. Potts"]

Using .each and string interpolation, print the following text to the Terminal...

Belle is friends with Chip Potts
Belle is friends with Cogsworth
Belle is friends with Lumière
Belle is friends with Mrs. Potts

# Your code goes here...

Ruby OOP

Question 4

Create Ruby classes for Animal and Lion. Each Animal should have...

• A name (String) attribute
• A greet instance method
• The ability to "get" and "set" name

Create a new Animal instance with the name "Pumba".

Make the Lion inherit from the Animal class. The Lion class should have a pack class variable that holds references to each instance created.

Each lion should have...

• A king (Boolean) attribute
• If the instance's name is "Simba", set the king attribute to true

Create a new lion instance with the name "Simba".

# Your code goes here...

SQL, Databases, and ActiveRecord

Question 5

Describe what an ERD is and why we create them for applications. Also give an example what the attributes and relationships might be for the following entities (no need to draw an ERD)...

• Genie
• Lamp
• Person
• Pet

Your answer goes here...

Question 6

Describe what a schema is and how we represent a one-to-many relationship in a SQL database.

Your answer goes here...

Question 7

Consider a class Person that inherits from ActiveRecord::Base and has the following schema...

class Person < ActiveRecord::Base
end

CREATE TABLE persons(
  id SERIAL PRIMARY KEY,
  name VARCHAR NOT NULL,
  age INT NOT NULL
);

Write Ruby code that will create an instance of a person...

# Your code goes here...

Question 8

Assuming the Person class from the previous question, write Ruby code that will query for any person that is 15 years of age...

# Your code goes here...

Question 9

Write a route in Sinatra that will print "Hello world" in the web browser at the following URL: http://localhost:4567/oh_hello

# Your code goes here...