Null Language-Independent Type for YAML™ Version 1.1

URI:

tag:yaml.org,2002:null

Shorthand:

!!null

Kind:

Scalar.

Canonical:

~

Regexp:

 ~ # (canonical)
|null|Null|NULL # (English)
| # (Empty)

Definition:

Devoid of value.

A null value is used to indicate the lack of a value. This is typically converted into any native null-like value (e.g., undef in Perl, None in Python). Note that a null is different from an empty string and that a mapping entry with some key and a null value is valid and different from not having that key in the mapping.

Example 1. !!null Examples

# A document may be null.
---
---
# This mapping has four keys,
# one has a value.
empty:
canonical: ~
english: null
~: null key
---
# This sequence has five
# entries, two have values.
sparse:
 - ~
 - 2nd entry
 -
 - 4th entry
 - Null