Select only non-empty objects from array-CodePudding

I have a JSON array with objects as items. Some of the objects have properties, some don't. How can I filter the list with jq to keep only non-empty objects in the list?

Input:

[
  {},
  { "x": 42 },
  {},
  { "y": 21 },
  {},
  { "z": 13 }
]

Expected output:

[
  { "x": 42 },
  { "y": 21 },
  { "z": 13 }
]

I tried jq 'select(. != {})', but the result still contains all items.

CodePudding user response：

You need map to make select test individual objects:

jq 'map(select(. != {}))'

CodePudding user response：

map is required to apply the filter to every item in the array. Then any can be used: it will return true for objects with at least one property, and false if the object is empty.

$ jq -n '{} | any'
false
$ jq -n '{x:42} | any'
true

Solution:

map(select(any))

CodePudding user response：

Just use the del filter:

jq 'del(.[] | select(length == 0))'

jq 'del(.[] | select(. == {}))'