eolas/Programming_Languages/YAML/Guide_to_YAML.md

categories	tags
Programming Languages

Guide to YAML

• Data description language
• Alternative to XML and JSON
• Easy to read by humans and process by code

Main rule

Never use tabs for indentation, use two spaces

Available data types

• strings
• numbers
• booleans
• arrays
• maps (key, value pairs)

Example

# Basic scalar data types
age: 51
greeting: Hello, world
length: 182.3
happy: true
``

```yaml
# array
pets:
  - cat
  - dog

# nested array
pets:
  - cat
  - dog
    - staffy
    - pitty

# map
languages:
  - java: advanced
  - python: average
  - javascript: basic

Strings

• Don't have to use quotes unless string contains reserved YAML characters (dashes, colons etc)
• Can use single or double quotes

Multi-line text

Two methods:

# Literal block preserves new line characters
literal_block: |
  Lorem ipsum dolar sit avcc lorem dolar 
  Blah blah
  Blah

folded_block: >
  Each different line
  will be folded back on itself so you don't
  have to keep scrolling to the right