To sort a JSON dictionary (or array of objects) based on one of its fields using jq on Linux, you can use the sort_by function. Here’s how you can do it:

Example: Sort by a Field

Suppose you have a JSON file (data.json) like this:

[
  {"name": "Alice", "age": 30},
  {"name": "Bob", "age": 25},
  {"name": "Charlie", "age": 35}
]

To sort this array of objects by the age field, use:

jq 'sort_by(.age)' data.json

Output:

[
  {"name": "Bob", "age": 25},
  {"name": "Alice", "age": 30},
  {"name": "Charlie", "age": 35}
]

If Your JSON is a Dictionary (Object)

If your JSON is a dictionary (object) and you want to sort its keys based on a field in the values, you can use to_entries, sort_by, and from_entries:

jq 'to_entries | sort_by(.value.age) | from_entries' data.json

Sort in Descending Order

To sort in descending order, add the - operator:

jq 'sort_by(.age) | reverse' data.json

or

jq 'sort_by(-.age)' data.json