---
title: Core · Basics
description: Fundamental value types every Ruby program uses.
canonical: https://rubydoc.ai/docs/core-basics.md
source: RubyDoc.AI
---

# Core · Basics

Fundamental value types every Ruby program uses.

- [Object](https://docs.ruby-lang.org/en/master/Object.html) — Root of Ruby's object hierarchy.
- [String](https://docs.ruby-lang.org/en/master/String.html) — Mutable sequence of characters.
- [Symbol](https://docs.ruby-lang.org/en/master/Symbol.html) — Interned, immutable identifier.
- [Integer](https://docs.ruby-lang.org/en/master/Integer.html) — Whole numbers of arbitrary size.
- [Float](https://docs.ruby-lang.org/en/master/Float.html) — Double-precision floating-point numbers.
- [Numeric](https://docs.ruby-lang.org/en/master/Numeric.html) — Abstract base of all number types.
- [TrueClass / FalseClass / NilClass](https://docs.ruby-lang.org/en/master/NilClass.html) — Boolean & nil singletons.
- [Range](https://docs.ruby-lang.org/en/master/Range.html) — Interval of values, e.g. (1..10).
- [Regexp](https://docs.ruby-lang.org/en/master/Regexp.html) — Regular expression pattern.

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Part of the [RubyDoc.AI](https://rubydoc.ai) documentation index. See also [docs.md](https://rubydoc.ai/docs.md) and [llms.txt](https://rubydoc.ai/llms.txt).