I have a JSON object that looks like this:
[{"name":"NAME_1"},"NAME_2"]
I would like an output of
["NAME_1", "NAME_2"]
Some of the entries in the array are an object with a key "name" and some are just a string of the name. I am trying to extract an array of the names. Using
jq -cr '.[].name // []'
throws an error as it is trying to index .name of the string object. Is there a way to check if it is a string, and if so just use its value instead of .name?
You can use the type function which returns "object" for objects.
jq '.[] | if type == "object" then .name else . end' file.json
To get the output as array, just wrap the whole expression into [ ... ].
echo '[{"name":"NAME_1"},"NAME_2"]' \
| jq '[ .[] | if (.|type) == "object" then .name else . end ]'
[
"NAME_1"
"NAME_2"
]
Ref:
As @LéaGris comments, a simpler version
jq '[ .[] | .name? // . ]' file
Just use the error suppression operator with ?, map and scalars
jq 'map( .name?, scalars )'
Note that by using scalars, it is assumed that other than objects with name, all others are names of form NAME_*. If there are other strings as well, and you need to exclude some of them you might need to add some additional logic to do that. e.g. using startswith(..) with a string of your choice.
map( .name?, select( scalars | startswith("NAME") ) )
With your shown samples only, please try following jq code. Using tostream function here to get the required values from requirement.
jq -c '[.[] | tostream | if .[1] != null then .[1] else empty end]' Input_file