Variables in Ruby Language

Ruby is a dynamic and versatile programming language known for its simplicity and ease of use. One of the funda

mental concepts in Ruby, as in many programming languages, is the use of variables. Variables are essential for storing and manipulating data in your programs. In this post, we’ll dive into the world of variables in Ruby, exploring their types, naming conventions, and how to use them effectively with practical examples.

Variable Types

Ruby has several types of variables:

1. Local Variables: Local variables are created by starting the variable name with a lowercase letter or an underscore. They are limited to the scope in which they are defined.

   name = "John"
   age = 30

2. Instance Variables: Instance variables begin with ‘@’ and are used to store object-specific data in Ruby classes.

   class Person
     def initialize(name)
       @name = name
     end
   end

3. Class Variables: Class variables are prefixed with ‘@@’ and are shared among all instances of a class.

   class Car
     @@total_count = 0
     def initialize
       @@total_count += 1
     end
   end

4. Global Variables: Global variables start with a dollar sign ‘$’ and can be accessed from anywhere in your Ruby program.

   $global_var = 42

5. Constant Variables: Constants begin with an uppercase letter and are used to store values that should not be changed during the program’s execution.

   MAX_SPEED = 100

Variable Naming Conventions

Ruby has some naming conventions for variables:

• Variable names should use snake_case (e.g., my_variable, user_age) for better readability.
• Start instance variables with ‘@’, class variables with ‘@@’, and global variables with ‘$’.
• Avoid using reserved words, as they have special meanings in Ruby.

Using Variables with Examples

Let’s look at some practical examples of using variables in Ruby:

Local Variables

name = "Alice"
age = 25

puts "My name is #{name} and I am #{age} years old."

Instance Variables

class Person
  def initialize(name)
    @name = name
  end

  def say_hello
    puts "Hello, my name is #{@name."
  end
end

alice = Person.new("Alice")
alice.say_hello

Class Variables

class BankAccount
  @@total_balance = 0

  def deposit(amount)
    @@total_balance += amount
  end

  def self.total_balance
    @@total_balance
  end
end

account1 = BankAccount.new
account1.deposit(100)
account2 = BankAccount.new
account2.deposit(200)

puts "Total balance in all accounts: #{BankAccount.total_balance}"