**Course Title:** Ruby Programming: From Basics to Advanced Techniques **Section Title:** Introduction to Ruby and Setup **Topic:** Writing your first Ruby program: Hello, World! **Introduction** Welcome to the Ruby Programming: From Basics to Advanced Techniques course! In this section, we will cover the basics of Ruby programming, including setting up a development environment and writing your first Ruby program. In this topic, we will focus on writing your first Ruby program, which is a classic "Hello, World!" program. **What is a "Hello, World!" Program?** A "Hello, World!" program is a simple program that prints the string "Hello, World!" to the screen. It is a classic example of a programming exercise that is often used to introduce beginners to a new programming language. **Why Write a "Hello, World!" Program?** Writing a "Hello, World!" program is an excellent way to get started with Ruby programming. It allows you to: * Get familiar with the Ruby syntax and basic data types * Understand how to write a simple program in Ruby * Learn how to use the Ruby interpreter to run your program **Setting Up Your Development Environment** Before we can write our first Ruby program, we need to set up our development environment. In the previous topic, we covered setting up a development environment using RubyInstaller, RVM, or rbenv. If you haven't already, please refer to that topic for instructions on how to set up your development environment. **Writing Your First Ruby Program** Now that we have our development environment set up, let's write our first Ruby program. Create a new file called `hello.rb` and add the following code: ```ruby # hello.rb # Print "Hello, World!" to the screen puts "Hello, World!" ``` Let's break down what's happening in this code: * `puts` is a method that prints its argument to the screen, followed by a newline character. * `"Hello, World!"` is a string literal that contains the text we want to print. **Running Your Program** To run your program, navigate to the directory where you saved the `hello.rb` file and type the following command: ``` ruby hello.rb ``` This will execute the `hello.rb` program and print "Hello, World!" to the screen. **Key Concepts** * Variables: In Ruby, variables are denoted by the `=` symbol. For example, `x = 5` creates a variable `x` that holds the value `5`. * Strings: Strings are denoted by double quotes `""`. For example, `"Hello, World!"` is a string literal that contains the text "Hello, World!". * Methods: Methods are blocks of code that can be called by name. For example, `puts` is a method that prints its argument to the screen. **Practical Takeaways** * Make sure to save your program in a file with a `.rb` extension. * Use the `ruby` command to run your program. * Use the `puts` method to print text to the screen. **Exercise** Try modifying the `hello.rb` program to print a different message to the screen. For example, you could print "Hello, [Name]!" where [Name] is a variable that holds the user's name. **Leave a Comment or Ask for Help** If you have any questions or need help with this topic, please leave a comment below. I'll be happy to assist you. **Next Topic: Conditional Statements** In the next topic, we will cover conditional statements, including `if`, `else`, `unless`, and `case`. This will help you learn how to make decisions in your Ruby programs and handle different scenarios. **External Resources** * Ruby Documentation: [https://ruby-doc.org/](https://ruby-doc.org/) * Ruby Tutorial: [https://www.ruby-lang.org/en/documentation/tutorials/](https://www.ruby-lang.org/en/documentation/tutorials/) I hope this helps! Let me know if you have any questions or need further clarification.