Data Types in Ruby

Explore Ruby's core data types including String, Integer, Float, Boolean, Nil, Symbol, Array, and Hash.

What Are Data Types?

A data type tells Ruby what kind of value a variable holds and what operations are valid on it. In Ruby, everything is an object — even integers and booleans.

1. Everything Is an Object

Unlike many languages, Ruby has no primitive types. Every value is an instance of a class.

Built-in Data Types

Ruby's built-in scalar types are Integer, Float, String, TrueClass/FalseClass (Boolean), NilClass, and Symbol.

1. Integer

Whole numbers of any size. Ruby automatically handles big integers.

2. Float

Decimal numbers following the IEEE 754 double-precision standard.

3. String

Sequences of characters. Double-quoted strings support interpolation; single-quoted strings are literal.

4. Boolean (TrueClass / FalseClass)

Ruby has `true` and `false`. They are singleton instances of `TrueClass` and `FalseClass`.

5. Nil (NilClass)

`nil` represents the absence of a value. It is Ruby's equivalent of `null` or `None`.

6. Symbol

Symbols are immutable, reusable identifiers starting with `:`. They are more memory-efficient than strings for keys.

Collection Data Types

Ruby's built-in collection types are Array (ordered list), Hash (key-value pairs), and Range (a sequence between two values).

1. Array

An ordered, indexed list of any objects.

2. Hash

A collection of key-value pairs. Keys are usually symbols.

3. Range

A Range represents a sequence between a start and end value.

Printing the Data Type

Ruby provides `.class`, `.is_a?`, `.kind_of?`, and `.instance_of?` to inspect and verify types at runtime.

1. .class

`.class` returns the class (type) of any object.

2. is_a? / kind_of? / instance_of?

These methods check whether an object belongs to a type or its ancestors.

Type Conversion

Ruby provides explicit conversion methods like `to_i`, `to_f`, `to_s`, `to_a`, and `to_sym` to convert between types.

1. Explicit Conversion Methods

Use `to_i`, `to_f`, `to_s`, `to_a`, `to_sym` to convert between types.

2. Strict Conversions (Integer(), Float())

`Integer()` and `Float()` are strict — they raise an error if the string is not a valid number.