Ruby

Ruby is a high-level dynamically typed language that is similar to Python.

Getting Started

Start up the Ruby REPL (irb) and enter the following:

def hi
  puts "Hello World!"
end

Now you should be able to write hi and it should output Hello World! and return nil. If a function has no parameters, you can call it by name; otherwise, use brackets. I think brackets are a good idea all of the time to remain explicit.

A class is made similarly:

class Greeter
  def initialize(name = "World")
    @name = name
  end
  def say_hi
    puts("Hello #{@name}!")
  end
  def say_bye
    puts("Bye, #{@name}, see you soon.")
  end
end

To instatiate this, you can call Greeter.new("Bob") or whatever name, and assign it to a variable. Then you can call the methods of this class instance from the variable. e.g. new_greeter.say_hi().

Classes can be modified after ther are defined, and these changes are retroactively propagated through all instances, since it is using the class as a reference.

Array Methods

Since I use these all the time and always forget which does what, I put the analogous Javascript method here for sake of lookup.

JS Method	Ruby Method	Example
forEach	each	`[1,2,3].each {
map	map	`[1,2,3].map {
filter	select	`[1,2,3].select {
reduce	inject	`[1,2,3].inject(0) {

References

Incoming Links

Last modified: 202401040446