Data Types & Interpolation

💎 Ruby Lesson 3 Beginner

Ruby is a purely object-oriented language. Every data type, including primitive numbers and strings, is an object containing built-in methods.

1 String Interpolation & Symbols

Ruby provides unique data types:

String Interpolation (`#{"#{expr}"}`): Double-quoted strings evaluate embedded code sequences wrapped in curly braces. Single-quoted strings do not perform evaluation and treat characters as literals.
Symbols (`:my_symbol`): Immutable, reusable string-like identifiers. Unlike strings, only one instance of a symbol exists in memory, making them excellent for hash keys.

2 Type Interpolation Code

Let's run a program exploring double-quoted evaluations and Symbols comparison:

Ruby — Data Types ▶ Run Code

item = "book"
price = 14.99

# Double quotes process interpolation
puts "The #{item} costs $#{price}"

# Symbols demo
status_ok = :ok
status_err = :error

puts "Symbol type: #{status_ok.class}"
puts "Comparing symbol IDs: #{:ok.object_id == :ok.object_id}"
puts "Comparing string IDs: #{"ok".object_id == "ok".object_id}"

3 Code Challenge

Challenge: Declare a string in single quotes and another in double quotes, both containing a variable interpolation sequence. Print both strings to verify the difference.