How to check if element exists in array with jq

Question

I have an array and I need to check if elements exists in that array or to get that element from the array using jq, fruit.json:

{
    \"fr         


        

Answer 1

To have jq return success if the array fruit contains "apple", and error otherwise:

jq -e '.fruit[]|select(. == "apple")' fruit.json >/dev/null

To output the element(s) found, omit >/dev/null. If searching for a fixed string, this isn't very relevant, but it might be if the select expression might match different values, e.g. if it's a regexp.

To output only distinct values, pass the results to unique.

jq '[.fruit[]|select(match("^app"))]|unique' fruit.json

will search for all fruits starting with app, and output unique values. (Note that the original expression had to be wrapped in [] in order to be passed to unique.)