Basic YAML Syntax and Data Types

Intermediate

✍️ YAML Syntax & Data Types

Understanding YAML syntax and data types is fundamental to writing effective YAML documents.

🔹 Core Data Types

🔤 Scalars

  • Strings: Can be unquoted or quoted ('single' or "double")
  • Numbers: Integers, floats
  • Booleans: true, false
  • Null: null or ~

📋 Sequences (Lists)

Represented as lists, indicated by dashes:

fruits:
  - Apple
  - Banana
  - Cherry

🔑 Mappings (Key-Value Pairs)

Use colons to separate keys and values:

person:
  name: Alice
  age: 28
  city: Wonderland

🧱 Indentation

  • Uses spaces only (tabs are discouraged)
  • Preferably 2 or 4 spaces
  • Consistent indentation is crucial for valid YAML

🧾 Multi-line Scalars

Use block style:

  • | for literal (preserves line breaks)
  • > for folded (folds into a single line)
description: |
  This is a multiline
  string that preserves line breaks.

♻️ Anchors & Aliases

Enable reuse of data snippets:

defaults: &defaults
  timeout: 30
  retries: 3

service:
  <<: *defaults
  name: MyService

✅ This supports DRY (Don't Repeat Yourself) principles in YAML documents.