W1D3 - States & Cities - Hash Exercise

README.md

Introduction

Goals:

• Practice using Hashes and Arrays
• Writing your code incrementally
• Create method for specific tasks
• Writing driver code for your methods, to test that they work correctly

Step-by-Step Tasks

Perform the tasks below, in order, within the state_info.rb ruby file.

Task 1

Insert two additional states into the Hash, but without modifying the initial Hash definition. Instead, add in these new kv pairs after the states object is defined.

Task 2

Declare another hash called cities where the keys are again the state code but the values are arrays of city names.

Add a few (2 to 4) cities for each state.

Task 3

Define a method describe_state that:

• Takes as input a state code (eg: 'CA')
• Returns the details of that state, including a list of its cities (eg: 'CA is for California. It has 2 major cities: San Francisco, LA')

Tips:

• The method should return the string, not output it
• Write test code to output the return value to make sure it works, like we have done with previous exercises
• Write the code incrementally:
  1. Write the empty method
  2. Write the test code after the method definition, that will actually be doing the puts of the method's return value.
  3. Implement a small part of the method instead of trying to have it return the final string. Eg: 'CA' is for California' only.
  4. Add more functionality and test code

Task 4

Declare another Hash called taxes which is responsible for defining taxes for each of the states (eg: 7.5 for 7.5%). You can just make up the values... though I cannot guarantee that the US Gov't will not come after you for misrepresenting their tax information.

Task 5

Define another method called calculate_tax which:

• Takes as input the state code as well as a dollar amount (eg: 123.49)
• Determines the tax rate to use based on the provided state
• Calculates the tax amount based on that rate
• Returns the tax amount rounded to 2 decimal places (eg: 44.53)

Refer to the same tips as Task 3

Task 6

Define a method find_state_for_city which should:

• Take as input the name of a city
• Return the state code for where that city is located

Of course, for your test code, find states for cities that are actually mentioned in your cities hash

Bonus Tasks (Optional)

Note: Please complete the required tasks prior to attempting this bonus.

Task 7

Refactor your code such that instead of having two separate hashes states and cities, you would just have one hash, and the information about the state name and all of its cities would be available in that one hash.

Task 8

Unless you've already done so previously, improve your methods to handle "edge cases" to make them more robust.

Examples:

• If an unknown state code is passed into the calculate_tax method it won't throw an error
• If a string state code (eg: 'MI' instead of :MI) is passed into a method, it can still recognize and find the desired state

state_info.rb

states = {
  OR: 'Oregon',
  FL: 'Florida',
  CA: 'California',
  NY: 'New York',
  MI: 'Michigan'
}