Object Oriented Practice Ideas

Use the ideas below to practice writing simple plain Ruby / JavaScript objects.

Setting up Ruby

To create a new challenge for yourself:

See the ruby/example directory for a working example of how to set it up.

To create a new challenge for yourself:

Make sure you have jasmine installed with npm install -g jasmine.
Create a new directory under javascript, cd into it, then run jasmine init
Run jasmine to run specs

See the javascript/example directory for a working example of how to set it up.

Create a class that can track who owes what amount for lunch, what they should tip, and what they actually paid.

Write a TipCalculator class
Make the constructor take one parameter for the tip percent (a decimal)
Write a method called "add" that takes a name (string) and an amount in cents (number)
Write a method called "owed" that takes a name (string) and returns the amount they owe in cents (the amount from add + their tip amount)
Write a method called "pay" that takes a name (string) and an amount
Write a method called "balance" that takes a name (string) and returns the amount owed in cents
Write a method called "summary" that returns an array of strings in the format Joe owed $x.xx and paid $x.xx and Joe's balance is $x.xx
Write a method called total that returns the total amount due
Write a method called tally that returns the total amount everyone has paid

Think of an example that has:

Some internal state that changes (like filling something up, traveling some distance, gaining or losing some quantity)
Has some data that can be represented with an array / hash (like songs in a playlist, or wine bottles in a bar)
Has some loop and / or aggregation (like the total of a bank balance)