1. What is Ruby?

Ruby is an open-source, high-level programming language designed for simplicity and productivity. Its syntax is elegant and easy to read, making it a great choice for beginners and experienced developers alike. Ruby is often used in web development, particularly with the Ruby on Rails framework.

2. Setting Up Your Environment

To get started with Ruby, you need to install the Ruby interpreter. You can install Ruby using the official website's instructions or use a version manager like rbenv or RVM to manage multiple Ruby versions on your system.

// Example of checking Ruby version:
ruby -v

3. Ruby Syntax

Ruby code is written in plain text files with the .rb extension. It is known for its simple and readable syntax, which focuses on minimizing complexity.

# Example:
puts "Hello, World!"

4. Variables and Data Types

Ruby supports dynamic typing, meaning variables do not require explicit data type declarations. Variables are prefixed with $ for global variables, @ for instance variables, and @@ for class variables.

# Example:
name = "Alice"   # String
age = 25         # Integer
height = 5.5     # Float
is_student = true # Boolean

5. Conditional Statements

Conditional statements in Ruby are used to execute code based on specific conditions. The common ones are if, elsif, and else.

# Example:
if age >= 18
  puts "You are an adult."
else
  puts "You are a minor."
end

6. Loops

Ruby provides several looping constructs, including while, for, and each. The each loop is commonly used for iterating over collections like arrays or hashes.

# Example of each loop:
[1, 2, 3, 4, 5].each do |number|
  puts number
end

7. Functions

Functions in Ruby are defined using the def keyword. Ruby allows methods to have default arguments and variable-length arguments.

# Example:
def greet(name="Stranger")
  puts "Hello, #{name}!"
end

greet("Alice")  # Output: Hello, Alice!
greet           # Output: Hello, Stranger!

8. Arrays

Arrays in Ruby are ordered collections that can store multiple values of different types. Arrays are zero-indexed.

# Example:
fruits = ["Apple", "Banana", "Orange"]
puts fruits[0]  # Output: Apple

9. Hashes

Hashes in Ruby are similar to dictionaries in other languages. They store key-value pairs and are commonly used to store associative data.

# Example:
person = { name: "Alice", age: 25, job: "Developer" }
puts person[:name]  # Output: Alice

10. File Handling

Ruby provides a simple and flexible way to work with files, allowing you to read from and write to files easily.

# Example of writing to a file:
File.open("example.txt", "w") do |file|
  file.puts "Hello, Ruby!"
end

# Example of reading from a file:
File.open("example.txt", "r") do |file|
  puts file.read
end

11. Object-Oriented Programming (OOP)

Ruby is an object-oriented language, meaning everything is an object. You can define classes, create objects, and use inheritance and polymorphism to organize your code in an efficient manner.

# Example:
class Person
  def initialize(name, age)
    @name = name
    @age = age
  end

  def greet
    puts "Hello, my name is #{@name} and I am #{@age} years old."
  end
end

person = Person.new("Alice", 25)
person.greet