jq how to get the last entry in an object

Question

I'm working with jq 1.6 to get the last entry in an object. It should work like this:

data='{ "1": { "a": "1" }, "2": { "a": "2" }, "3": { "a": "3" } }'
result=`echo $data | jq 'myfilter'`
echo $result
{ "3": { "a": "3" } }

I tried these filters:

jq '. | last' # error: Cannot index object with number

How can I tell jq to quote the number?

jq '. | to_entries | last' # { "key": "3", "value": { "a": "3" } }

I guess I could munge this up by concatenating the key and value entries. Is there a simpler way?

The tutorial and the manual didn't help. No joy on SO either.

Answer 1

You can use the following :

jq 'to_entries | [last] | from_entries'

Try it here.

We can't use with_entries(last) because last returns a single element and from_entries requires an array, hence the [...] construct above.