slin12 / advanced-hashes-hashketball-prework

Hashketball

Objectives

1. Practice building nested hashes.
2. Practice iterating over nested hashes.

Instructions

Great news! You're going to an NBA game. The only catch is that you've been volunteered to keep stats at the game.

Fork and clone this lab and run the test suite to get started. You'll be coding your solution in hashketball.rb.

Part 1: Building the Hash

The first method you will define is called game_hash. This method contains and returns a hash nested in the following manner:

• The top level of the hash has two keys: :home, for the home team, and :away, for the away team.
• The values of the :home and :away keys are hashes. These hashes have the following keys:
  • :team_name
  • :colors
  • :players
• The :team_name key points to a string of the team name.
• The :colors key points to an array of strings that are that team's colors.
• The :players key points to a hash of players whose names (as strings) are the keys to a hash containing their stats. The values for each player's names and their stats can be found in the table below. The stats keys should be formatted like this:
  • :number
  • :shoe
  • :points
  • :rebounds
  • :assists
  • :steals
  • :blocks
  • :slam_dunks

Use the following data to populate your game_hash as outlined above. Remember to run learn to see what the tests expect.

Home Team:

• team name: Brooklyn Nets
• colors: Black, White
• players:

Stat	Info	Info	Info	Info	Info
Player Name	Alan Anderson	Reggie Evans	Brook Lopez	Mason Plumlee	Jason Terry
Number	0	30	11	1	31
Shoe	16	14	17	19	15
Points	22	12	17	26	19
Rebounds	12	12	19	12	2
Assists	12	12	10	6	2
Steals	3	12	3	3	4
Blocks	1	12	1	8	11
Slam Dunks	1	7	15	5	1

Away Team:

• team name: Charlotte Hornets
• colors: Turquoise, Purple
• players:

Stat	Info	Info	Info	Info	Info
Player Name	Jeff Adrien	Bismak Biyombo	DeSagna Diop	Ben Gordon	Brendan Haywood
Number	4	0	2	8	33
Shoe	18	16	14	15	15
Points	10	12	24	33	6
Rebounds	1	4	12	3	12
Assists	1	7	12	2	12
Steals	2	7	4	1	22
Blocks	7	15	5	1	5
Slam Dunks	2	10	5	0	12

Step 2: Building Methods

Calling Methods within Methods

You'll be building a series of methods that operate on the above game hash to return certain information about the teams and players. Each method will operate on the game hash by calling the game_hash method that returns the game_hash. In other words, since our game_hash method returns our hash, you can think of the game_hash like a variable that points to our hash and operate on it just as you would with hashes in previous lessons.

For example, let's say we want to build a method, home_team_name, that returns the name of the home team, "Brooklyn Nets". We can call the method game_hash inside of our home_team_name method and operate on the game_hash:

def home_team_name
  game_hash[:home][:team_name]
end

puts home_team_name
# => "Brooklyn Nets"

Now that we understand how we are going to operate on the game_hash inside of the methods we're building, let's build those methods:

Iterating through Nested Levels:

This lab requires us to iterate through the many levels of our nested hash. DON'T TAKE YOUR UNDERSTANDING OF YOUR HASH FOR GRANTED. Every time you iterate into a new level of the hash, immediately place a binding.pry there. Then, run RSpec with the learn command to see what the key/value pairs of that hash are.

Let's take a look at an example:

def good_practices
  game_hash.each do |location, team_data|
    #are you ABSOLUTELY SURE what 'location' and 'team data' are? use binding.pry to find out!
    binding.pry
      team_data.each do |attribute, data|
        #are you ABSOLUTELY SURE what 'attribute' and 'team data' are? use binding.pry to find out!
        binding.pry

        #what is 'data' at each loop through out .each block? when will the following line of code work and when will it break?
        data.each do |data_item|
            binding.pry
      end
    end
  end
end

Open up the hashketball.rb file and add the line require "pry" at the top and copy and paste the above method. Then, beneath the end that closes the method definition, call the method (good_practices) and, in your terminal, run the file with ruby hashketball.rb. Play around with the methods in each binding until you get comfortable with the iteration. This should give you a stronger sense of how we iterate through so many levels of a nested hash and what happens on each level. Use this method of placing LOTS of bindings when you iterate in order to solve this lab.

Okay, now we're ready to build out methods:

Method Building

• Build a method, num_points_scored that takes in an argument of a player's name and returns the number of points scored for that player.

  • Think about where in the hash you will find a player's :points. How can you iterate down into that level? Think about the return value of your method. Remember that .each returns the original collection that you are iterating over. How can you return the number of points for a particular player?

• Build a method, shoe_size, that takes in an argument of a player's name and returns the shoe size for that player.

  • Think about how you will find the shoe size of the correct player. How can you check and see if a player's name matches the name that has been passed into the method as an argument?

• Build a method, team_colors, that takes in an argument of the team name and returns an array of that teams colors.

• Build a method, team_names, that operates on the game hash to return an array of the team names.

• Build a method, player_numbers, that takes in an argument of a team name and returns an array of the jersey number's for that team.

• Build a method, player_stats, that takes in an argument of a player's name and returns a hash of that player's stats.

  • Check out the following example of the expected return value of the player_stats method:

    player_stats("Alan Anderson")
    => { :number => 0,
         :shoe => 16,
         :points => 22,
         :rebounds => 12,
         :assists => 12,
         :steals => 3,
         :blocks => 1,
         :slam_dunks => 1
       }

• Build a method, big_shoe_rebounds, that will return the number of rebounds associated with the player that has the largest shoe size. Break this one down into steps:

  • First, find the player with the largest shoe size
  • Then, return that player's number of rebounds
  • Remember to think about return values here. Use binding.pry to drop into your method and understand what it is returning and why.

Bonus Questions:

Define methods to return the answer to the following questions:

1. Which player has the most points? Call the method most_points_scored.

2. Which team has the most points? Call the method winning_team.

3. Which player has the longest name? Call the method player_with_longest_name.

Super Bonus:

1. Write a method that returns true if the player with the longest name had the most steals. Call the method long_name_steals_a_ton?.

Resources

• Codecademy - A Night at the Movies

View Hashketball on Learn.co and start learning to code for free.