Ruby Variables & Strings

About Ruby

Ruby is a dynamic, object-oriented programming language designed to make programming expressive and enjoyable. It is often paired with Ruby on Rails for database-backed websites and applications.

• Rails web applications
• Scripting
• Prototypes

Created by

Yukihiro “Matz” Matsumoto

First released

1995 · first public release

Version / standard

Ruby 4.0

Current stable release line. Check framework compatibility before upgrading.

In the real world

• GitHub: Its Ruby on Rails web application
• Shopify: Its commerce platform with Rails
• 37signals: Basecamp and other Rails products

Facts checked 8 September 2026. Links open the sources; examples describe specific products or documented uses.

Syntax

name = "Ada"
puts "Hello, #{name}"

Examples

name = "Ada"
lessons = 3
puts "#{name} completed #{lessons} lessons"

name = "Ada"
visits = 3
puts "#{name} has #{visits} visits."

Best practices

• Use meaningful local-variable names and prefer interpolation instead of manually concatenating values into strings.
• Keep examples small while learning, then combine the idea with a real project.

At a glance

Purpose

Expressive scripting and applications

File extension

.rb

Runs in

Ruby interpreter

Usually used with

Ruby standard library and gems

In plain English

Ruby variable names refer to objects. Assigning a new value can make the same local name refer to a different object.

What you’ll learn

• Assign a local variable.
• Read its value.
• Build a string with interpolation.

Breaking down the syntax

name = value

Assigns a value to a local name.

#{...}

Inserts an expression into a double-quoted string.

puts

Writes a value with a newline.

How it works

Assign

Bind a local name.

Build text

Interpolate values into a string.

Output

Print the message.

When should I use this?

Give meaningful names to values in a script or method.

Common mistakes

A common trap

An uppercase initial letter declares a constant name rather than a local variable.

Incorrect

Name = "Ada" # constant, not a local variable

Corrected

name = "Ada" # local variable

Compare approaches

• Local variable: Use a lowercase or underscore initial character.
• Instance variable: Use @name for state belonging to an object.

Explore deeper

Assignment and object mutation differ

Reassigning a local name changes what that name refers to. Mutating a shared object can affect other references to the same object.

Specifications & further reading

• Official language reference for this topic

Related Ruby documentation