yq/operators/keys.md

Keys

Use the keys operator to return map keys or array indices.

Map keys

Given a sample.yml file of:

dog: woof
cat: meow

then

yq eval 'keys' sample.yml

will output

- dog
- cat

Array keys

Given a sample.yml file of:

- apple
- banana

then

yq eval 'keys' sample.yml

will output

- 0
- 1