**Course Title:** Ruby Programming: From Basics to Advanced Techniques **Section Title:** Introduction to Ruby and Setup **Topic:** Basic Ruby syntax: Variables, data types, and operators **Introduction** In the previous topics, we covered the history and features of Ruby and set up a development environment. Now, it's time to dive into the basics of Ruby syntax. In this section, we'll explore variables, data types, and operators. Understanding these fundamental concepts is crucial for writing efficient and effective Ruby code. **Variables** In Ruby, a variable is a name given to a value. Variables are used to store and manipulate data. There are several types of variables in Ruby, including: * Local variables: start with a lowercase letter or underscore (e.g., `hello` or `_hello`) * Instance variables: start with a single at sign (@) (e.g., `@hello`) * Class variables: start with a double at sign (@@) (e.g., `@@hello`) * Global variables: start with a dollar sign ($) (e.g., `$hello`) When assigning a value to a variable, use the assignment operator (=). Example: ```ruby # Assign a string value to a local variable greeting = "Hello, World!" # Print the value of the variable puts greeting # Output: Hello, World! ``` **Data Types** Ruby has several built-in data types: 1. **Numbers**: * Integers: whole numbers (e.g., `1`, `2`, etc.) * Floats: decimal numbers (e.g., `3.14`, `-0.5`, etc.) 2. **Strings**: sequences of characters (e.g., `"hello"`, `'hello'`, etc.) Strings can be enclosed in single quotes or double quotes. Double quotes allow for string interpolation. 3. **Boolean**: true or false values 4. **Symbols**: unique identifiers (e.g., `:hello`, `: world`, etc.) Symbols are often used as hash keys or for method names. 5. **Arrays**: ordered collections of objects (e.g., `[1, 2, 3]`, `[]`, etc.) 6. **Hashes**: unordered collections of key-value pairs (e.g., `{a: 1, b: 2}`, `{}`, etc.) Example: ```ruby # Create an array fruits = ["apple", "banana", "orange"] # Create a hash person = {name: "John", age: 30} # Print the values puts fruits[0] # Output: apple puts person[:name] # Output: John ``` **Operators** Ruby has various operators for performing arithmetic, comparison, logical, and assignment operations. 1. **Arithmetic Operators**: * `+` (addition) * `-` (subtraction) * `*` (multiplication) * `/` (division) * `%` (modulus) * `**` (exponentiation) 2. **Comparison Operators**: * `==` (equal to) * `!=` (not equal to) * `>` (greater than) * `<` (less than) * `>=` (greater than or equal to) * `<=` (less than or equal to) 3. **Logical Operators**: * `&&` (and) * `||` (or) * `!` (not) 4. **Assignment Operators**: * `=` (assignment) * `+=` (addition assignment) * `-=` (subtraction assignment) * `*=` (multiplication assignment) * `/=` (division assignment) * `%=` (modulus assignment) * `**=` (exponentiation assignment) Example: ```ruby # Arithmetic operation a = 5 b = 3 puts a + b # Output: 8 # Comparison operation puts a == b # Output: false # Logical operation puts a > b && a < 10 # Output: true ``` **Conclusion** In this section, we've covered the basics of Ruby syntax, including variables, data types, and operators. These fundamental concepts are essential for writing effective Ruby code. Practice using these concepts by writing simple Ruby programs. **Practical Exercise** 1. Create a Ruby program that asks the user for their name and age. Store the input values in variables. 2. Use the variables to display a personalized greeting message. 3. Experiment with different data types and operators to perform arithmetic and comparison operations. **Reference Materials** * Ruby documentation: [https://ruby-doc.org/](https://ruby-doc.org/) * Ruby syntax guide: [https://www.ruby-lang.org/en/documentation/](https://www.ruby-lang.org/en/documentation/) * Ruby tutorials: [https://www.tutorialspoint.com/ruby/index.htm](https://www.tutorialspoint.com/ruby/index.htm) **Leave a comment or ask for help** If you have any questions or need further clarification on any of the topics covered in this section, feel free to leave a comment below. We'll be happy to help. **Next Topic** In the next section, we'll write our first Ruby program: "Hello, World!".