Ruby Fundamentals Overview

You’ll learn the fundamentals of procedural and object oriented Ruby and reinforce your learning throughout by cumulatively building a Tic Tac Toe command line application game. In this way you’ll learn how to think like a programmer and structurally break down complicated problems into smaller components. Below is a general overview of what's covered. You'll notice that many of the concepts below will look familiar to you as you've already covered them in the Javascript units.


  • Debug Ruby Programs using IRB
  • Explain how to debug code by running tests and solving error messages
  • Identify four common types of error messages

Variables and Arrays

  • Create and declare variables
  • List and create the six data types in Ruby
  • Create and manipulate arrays


  • Create methods that take in single, multiple, and no arguments
  • Return values from methods
  • Read and describe the various parts of error messages in tests

Command Line Applications

  • Define command line applications as programs that interact directly with the computer’s shell and terminal
  • Describe the file structure of a CLI
  • Capture user input in a CLI
  • Build a simple CLI

Logic and Conditionals

  • Use conditional statements and comparison operators to control the flow of a program

Loops and Iteration

  • Use looping to tell a program to perform a repetitive action
  • Build methods using while and until loops
  • Distinguish between looping and iteration
  • Iterate over arrays using boolean enumerators (#all?, #none?, #any?, #include?)
  • Iterate over arrays using search enumerators (#select, #detect, #reject)
  • Create and iterate over nested arrays

Object Orientation

  • Describe Ruby classes and create instances of a class
  • Call and build instance methods on an object
  • Distinguish between instance and local variables
  • Explain how instance variables give objects attributes and properties
  • Define methods that read and write to instance variables
  • Create object properties using methods and instance variables
  • Build and use setter and getter methods
  • Instantiate instances of classes

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