How do I create an empty array in YAML?

Question

array_with_three_elements:
- 1
- 2
- 3

empty_array:

Is there any way to specify that empty_array: is an array with no elements, such as with []? When I load it into a ruby hash I'd like it to know that it's an array.

maerics · Accepted Answer · 2011-02-24 22:50:10Z

522

Try using [], like:

empty_array: []

So in Ruby you have:

x = YAML::load("empty_array: []")
x # => {"empty_array" => []}

edited Feb 24, 2011 at 22:50

answered Feb 24, 2011 at 20:54

maerics

157k47 gold badges277 silver badges299 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Mike A. Over a year ago

I just wanted to add that you can go into irb and type something like: "require 'yaml'; YAML::dump({ :hi => [] })" to see what the yaml should be for an object.

Daniel H Over a year ago

I'd just like to point out that JSON is an official subset of YAML 1.2 and almost a subset of earlier versions. Thus [] works for an empty sequence, "" works for an empty string, and {} works for an empty mapping.

oHo Over a year ago

@DanielH Note that YAML parsers may not support line breaks inside [] or {} structures, which is a major incompatibility with JSON (copy-paste from Wikipedia) Cheers

Daniel H Over a year ago

Many parsers are still on YAML 1.1; this is probably what Wikipedia is talking about. The entire point of the 1.2 release is to make JSON an official subset.

maurice Over a year ago

The reason I ended up on this page is that empty_array:[] resulted in a parser error. It apparently only happens in certain contexts. YAML::load("empty_array:[]") works, YAML::load("{empty_array:[]}") fails, and YAML::load("{empty_array: []}") also works. Beware of whitespace in yaml.

|

Collectives™ on Stack Overflow

How do I create an empty array in YAML?

1 Answer 1

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related