What is Ruby?

Ruby is a dynamic, object-oriented programming language designed for simplicity and productivity. Created by Yukihiro Matsumoto (Matz) in 1995, Ruby emphasizes programmer happiness and follows the principle of "least surprise" - meaning the language behaves in ways that programmers would naturally expect.

Key Features

Object-Oriented Design

Ruby is a pure object-oriented language where everything is an object, including numbers and strings. This creates a consistent and intuitive programming experience.

# Everything is an object
5.times { puts "Hello" }
"hello".upcase
[1, 2, 3].map { |x| x * 2 }

Dynamic Typing

Ruby is dynamically typed, meaning you don't need to declare variable types. The interpreter determines types at runtime.

name = "Alice"        # String
age = 25             # Integer
height = 5.6         # Float
is_student = true    # Boolean

Blocks and Iterators

Ruby's block syntax makes iteration and functional programming elegant and readable.

# Traditional loop
(1..5).each do |i|
  puts i
end

# Functional style
numbers = [1, 2, 3, 4, 5]
squares = numbers.map { |n| n ** 2 }
evens = numbers.select { |n| n.even? }

Popular Frameworks

Ruby on Rails

The most famous Ruby framework, Rails follows the "Convention over Configuration" principle and enables rapid web development.

# Rails controller example
class UsersController < ApplicationController
  def index
    @users = User.all
  end
  
  def show
    @user = User.find(params[:id])
  end
end

Sinatra

A lightweight web framework for simple applications and APIs.

require 'sinatra'

get '/' do
  "Hello, World!"
end

get '/users/:id' do
  "User #{params[:id]}"
end

Ruby Gems

Ruby's package manager, RubyGems, provides access to thousands of libraries and tools.

# Install a gem
gem install rails

# Use in your code
require 'json'
require 'net/http'

When to Use Ruby

Web Development

Automation and Scripting

Prototyping

Ruby vs Other Languages

Compared to Python

Compared to JavaScript

Getting Started

Installation

# Using rbenv (recommended)
brew install rbenv
rbenv install 3.2.0
rbenv global 3.2.0

# Using RVM
curl -sSL https://get.rvm.io | bash -s stable
rvm install ruby-3.2.0

First Ruby Program

# hello.rb
puts "Hello, Ruby World!"

# Run with: ruby hello.rb

Best Practices

Code Style

Testing

Ruby continues to be a popular choice for web development, automation, and learning programming due to its elegant syntax, strong community, and powerful frameworks like Rails.