Ruby Syntax

Learn the basic rules of Ruby programming

📝 Ruby Syntax Basics

Ruby syntax is designed to be natural and readable. It uses simple keywords and minimal punctuation, making code look clean and elegant. Ruby is case-sensitive and uses indentation for readability, though not required. 


# Simple Ruby syntax
puts "Hello, World!"
name = "Ruby"
puts "I love #{name}!"

Output: 

Hello, World!
I love Ruby!

Syntax Rules

🔤

Case Sensitive

Ruby distinguishes between cases 

name = "Ruby"
Name = "Python"
# Different variables!
📏

No Semicolons

Line breaks end statements 

puts "Hello"
puts "World"
# No semicolons needed
🎯

Keywords

Reserved words with special meaning 

if, else, end
def, class, module
true, false, nil
✨

Flexible

Multiple ways to write code 

puts("Hello")
puts "Hello"
# Both work!

🔹 Basic Output

Ruby provides several methods to display output. The most common are puts, print, and p, each with slightly different behavior. 

# puts - prints with newline
puts "Hello"
puts "World"

# print - prints without newline
print "Hello "
print "World"

# p - prints with inspect (useful for debugging)
p "Hello"

Output: 

Hello
World
Hello World
"Hello"

🔹 String Interpolation

Ruby allows you to embed variables and expressions inside strings using #{} syntax. This makes string formatting clean and readable. 

# String interpolation with #{}
name = "Alice"
age = 25

puts "My name is #{name}"
puts "I am #{age} years old"
puts "Next year I'll be #{age + 1}"

# Single quotes don't interpolate
puts 'My name is #{name}'  # Prints literally

Output: 

My name is Alice
I am 25 years old
Next year I'll be 26
My name is #{name}

🔹 Code Blocks

Ruby uses keywords like if, def, and class to start blocks, and end to close them. Proper indentation makes code readable.

🔸 If Statement 

# If-else block
age = 20

if age >= 18
  puts "You are an adult"
  puts "You can vote"
else
  puts "You are a minor"
end

Output: 

You are an adult
You can vote

🔸 Method Definition 

# Define a method
def greet(name)
  puts "Hello, #{name}!"
  puts "Welcome to Ruby"
end

# Call the method
greet("Bob")

Output: 

Hello, Bob!
Welcome to Ruby

🔹 Naming Conventions

Ruby follows specific naming conventions that make code consistent and readable across projects:

Variable Names:

  • Local variables: lowercase with underscores (snake_case)
  • Constants: UPPERCASE with underscores
  • Instance variables: start with @ symbol
  • Class variables: start with @@ symbols 
# Naming examples
user_name = "Alice"        # Local variable
MAX_SIZE = 100             # Constant
@age = 25                  # Instance variable
@@count = 0                # Class variable

# Method names (snake_case)
def calculate_total
  puts "Calculating..."
end

# Class names (CamelCase)
class UserAccount
  # class code
end

🔹 Operators

Ruby supports standard operators for arithmetic, comparison, and logical operations:

🔸 Arithmetic Operators 

# Basic math
puts 10 + 5    # Addition: 15
puts 10 - 5    # Subtraction: 5
puts 10 * 5    # Multiplication: 50
puts 10 / 5    # Division: 2
puts 10 % 3    # Modulus: 1
puts 2 ** 3    # Exponent: 8

Output: 

15
5
50
2
1
8

🔸 Comparison Operators 

# Comparisons
puts 5 == 5    # Equal: true
puts 5 != 3    # Not equal: true
puts 5 > 3     # Greater than: true
puts 5 < 3     # Less than: false
puts 5 >= 5    # Greater or equal: true
puts 5 <= 3    # Less or equal: false

Output: 

true
true
true
false
true
false

🔹 Multiple Statements

You can write multiple statements on one line using semicolons, though it's not recommended for readability: 

# Multiple lines (preferred)
name = "Ruby"
version = 3.2
puts "#{name} #{version}"

# One line with semicolons (not recommended)
name = "Ruby"; version = 3.2; puts "#{name} #{version}"

Output: 

Ruby 3.2
Ruby 3.2

🔹 Parentheses in Method Calls

Ruby allows you to omit parentheses in method calls, making code more natural to read: 

# With parentheses
puts("Hello")
print("World")

# Without parentheses (more Ruby-like)
puts "Hello"
print "World"

# Both styles work the same
def greet(name)
  "Hello, #{name}"
end

puts greet("Alice")
puts greet "Bob"

Output: 

Hello
WorldHello
World
Hello, Alice
Hello, Bob

🧠 Test Your Knowledge

Which keyword ends a code block in Ruby?