Add a new key/value to every object in json array in file with jq

Question

I have a json file like below. I want to add "stable": "yes" to every object in this file with jq. How can i do this?

 [
    {
        "id":"1",
        "name":"Blue"
    },
    {
        "id":"2",
        "name":"Red"
    }
 ]

I want it to be like this:

 [
    {
        "id":"1",
        "name":"Blue",
        "stable": "yes"
    },
    {
        "id":"2",
        "name":"Red",
        "stable": "yes"
    }
 ]

chepner · Accepted Answer · 2018-10-11 17:12:01Z

8

map and + will do this:

$ jq 'map(. + {stable: "yes"})' tmp.json
[
  {
    "id": "1",
    "name": "Blue",
    "stable": "yes"
  },
  {
    "id": "2",
    "name": "Red",
    "stable": "yes"
  }
]

Since the input is an array, the . refers to each object in that array, to which we add another object.

Note this will also override any existing stable key in each object.

edited Oct 11, 2018 at 17:12

answered Oct 11, 2018 at 14:33

chepner

538k77 gold badges594 silver badges747 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

somethingyouwant Over a year ago

What if it is like this { "data": [ { "id":"1", "name":"Blue" }, { "id":"2", "name":"Red" }]}

chepner Over a year ago

Modify the filter to update the data key of the top-level object: .data |= map(...). The |= operator pipes the left-hand side through the right-hand side, updating the original input in the process.

somethingyouwant Over a year ago

It just outputs it to the console but it doesn't write it to the file?

chepner Over a year ago

@somethingyouwant jq won't edit the file in place; you'll need to redirect to a second file and then replace the original.

peak Over a year ago

... or use sponge (or equivalent -- see especially stackoverflow.com/questions/6604852/…)

Collectives™ on Stack Overflow

Add a new key/value to every object in json array in file with jq

1 Answer 1

5 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related