YAML Ain’t Markup Language (YAML)

YAML addresses the same domain as JSON. One can describe the same objects as one could with JSON. YAML is easier to read by humans, though, and YAML supports comments, which JSON does not.

A downside of YAML could be that its meaning depends on the indentation of each individual line. This could make YAML files somewhat hard to read and maintain if there are many levels.

Some rules, to get an idea:

• YAML files should start with ---.
• a: b indicates a field “a” with the value “b”.
• - item 1 indicates an item of an Array.
• a: is the beginning of a Dictionary or Array. On the next line increase the indentation, and either declare a field or an item.
• Anything after a # is a comment.
• Values usually don’t have to be quoted. It is only necessary if it contains special characters like a :.
• The data type of a value is determined by its content (but could be set explicitly, which rarely happens). I.e. “John” is a string, “true” and “yes” are booleans, “3.5” is a floating point, etc.
• YAML supports multi-line strings.
• YAML supports IDs and References.

invoice: 12345
date: 2022-12-12
bill-to: &id001
  firstname: Bruce
  lastname: Wayne
  address:
    lines: |
      1007 Mountain Drive
      Suite #292
    city: Gotham
ship_to: *id001
product:
  - name: Batarang
    amount: 5
    price: 26
  - name: Grappling Gun
    amout: 1
    price: 873

​​ References

• https://yaml.org/spec/1.2.2/ Open external link