What is YAML?

YAML stands for YAML Ain't Markup Language (a recursive acronym). It started as "Yet Another Markup Language" but was redefined to distance itself from just being a markup language like XML.

• Human-Readable: It's clean and easy to write and understand, much more so than JSON or XML.
• Data-Oriented: It's designed to represent data structures (like lists and dictionaries) rather than documents.
• Versatile: It can represent scalars (single values), lists, and associative arrays (dictionaries/hashes).

Common Use Cases:

• Configuration files (Docker, Kubernetes, Ansible, GitHub Actions)
• Data serialization (exchanging data between languages)
• Property files

The Absolute Basics: Syntax & Structure

1. Key-Value Pairs (Maps/Dictionaries)

name: John Doe
age: 30
city: New York

2. Lists (Sequences)

fruits:
  - Apple
  - Banana
  - Orange

fruits: [Apple, Banana, Orange]

3. Nested Structures

person:
  name: John Doe
  age: 30
  hobbies:
    - hiking
    - reading
    - coding
  address:
    street: 123 Main St
    city: New York

YAML vs. JSON

Quick Start Guide

1. Start Simple: Begin with key-value pairs.
2. Indent with Spaces: Always use 2 or 4 spaces, never tabs.
3. Use a Linter/Validator: Many online tools and code editor plugins (like YAML plugins for VS Code) can validate your YAML and catch errors before you run your code.
4. Practice: Look at configuration files for tools like Docker Compose or GitHub Actions to see real-world examples.