Skip to content

Latest commit

 

History

History
101 lines (74 loc) · 3.27 KB

instructions.md

File metadata and controls

101 lines (74 loc) · 3.27 KB
Raw

Instructions

In this exercise, you're implementing a way to keep track of the high scores for the most popular game in your local arcade hall.

1. Define a new high score map

To make a new high score map, define the HighScore.new/0 function which doesn't take any arguments and returns a new, empty map of high scores.

HighScore.new()
# => %{}

2. Add players to the high score map

To add a player to the high score map, define HighScore.add_player/3, which is a function which takes 3 arguments:

  • The first argument is the map of scores.
  • The second argument is the name of a player as a string.
  • The third argument is the score as an integer. The argument is optional, implement the third argument with a default value of 0.

Store the default initial score in a module attribute. It will be needed again.

score_map = HighScore.new()
# => %{}
score_map = HighScore.add_player(score_map, "Dave Thomas")
# => %{"Dave Thomas" => 0}
score_map = HighScore.add_player(score_map, "José Valim", 486_373)
# => %{"Dave Thomas" => 0, "José Valim"=> 486_373}

3. Remove players from the score map

To remove a player from the high score map, define HighScore.remove_player/2, which takes 2 arguments:

  • The first argument is the map of scores.
  • The second argument is the name of the player as a string.
score_map = HighScore.new()
# => %{}
score_map = HighScore.add_player(score_map, "Dave Thomas")
# => %{"Dave Thomas" => 0}
score_map = HighScore.remove_player(score_map, "Dave Thomas")
# => %{}

4. Reset a player's score

To reset a player's score, define HighScore.reset_score/2, which takes 2 arguments:

  • The first argument is the map of scores.
  • The second argument is the name of the player as a string, whose score you wish to reset.

The function should also work if the player doesn't have a score.

score_map = HighScore.new()
# => %{}
score_map = HighScore.add_player(score_map, "José Valim", 486_373)
# => %{"José Valim"=> 486_373}
score_map = HighScore.reset_score(score_map, "José Valim")
# => %{"José Valim"=> 0}

5. Update a player's score

To update a player's score by adding to the previous score, define HighScore.update_score/3, which takes 3 arguments:

  • The first argument is the map of scores.
  • The second argument is the name of the player as a string, whose score you wish to update.
  • The third argument is the score that you wish to add to the stored high score.

The function should also work if the player doesn't have a previous score - assume the previous score is 0.

score_map = HighScore.new()
# => %{}
score_map = HighScore.add_player(score_map, "José Valim", 486_373)
# => %{"José Valim"=> 486_373}
score_map = HighScore.update_score(score_map, "José Valim", 5)
# => %{"José Valim"=> 486_378}

6. Get a list of players

To get a list of players, define HighScore.get_players/1, which takes 1 argument:

  • The first argument is the map of scores.
score_map = HighScore.new()
# => %{}
score_map = HighScore.add_player(score_map, "Dave Thomas", 2_374)
# => %{"Dave Thomas" => 2_374}
score_map = HighScore.add_player(score_map, "José Valim", 486_373)
# => %{"Dave Thomas" => 2_374, "José Valim"=> 486_373}
HighScore.get_players(score_map)
# => ["Dave Thomas", "José Valim"]