Material on YAML configuration files

An introductory guide to .yml (YAML) configuration files, commonly used in web projects like Jekyll, GitHub Actions, and many other tools.

⚙️ What Is a YML File?

YML (or YAML) stands for YAML Ain’t Markup Language, a configuration file format designed to be human-readable and neatly structured.

It is often used for settings, configuration data, or deployment pipelines in various apps and frameworks.

🧩 Key Features of YML Format

• Based on indentation (uses spaces, not tabs)
• No use of {} or [] for structure
• Uses : to separate keys and values
• Supports arrays, objects, and nested data

📘 Basic Example of a .yml Config

title: My Blog
description: Learning Web Development
author: Zaki
theme: minima

In the example above:

• title, description, author, and theme are keys
• The part after the : is the value

🧱 Nested (Hierarchical Data)

user:
  name: Zaki
  email: zaki@example.com

This structure means the object user has two properties: name and email.

📚 Example of Array/List in YML

skills:
  - HTML
  - CSS
  - JavaScript
  - Python

This list contains multiple items under the skills key.

🔧 Example from Jekyll _config.yml

In a Jekyll project (like a portfolio website), the config.yml file typically contains settings like:

title: Home
baseurl: ""
url: "https://m-zakifahrezi.github.io/"

sass:
  sass_dir: _sass
  style: compressed

theme: null

• baseurl is usually left empty if the site is at root.
• url is your GitHub Pages site address.
• plugins can be added depending on the features you want to enable.

⚠️ Important Tips When Using YML

• Use 2 or 4 spaces consistently for indentation.
• Avoid tabs, as they can cause parsing errors.
• Double-check the position of keys and values — a small mistake can make the config unreadable.

✅ Conclusion

• .yml is an important configuration file format used in many modern projects.
• It is easy to read and write, but very sensitive to indentation.
• Understanding YAML will help you when working with Jekyll, GitHub Actions, Netlify, and other tools.

💡 Learn how to write key-value pairs, arrays, and nested structures in YML to ensure your site configurations work smoothly!