How do I use jq to convert number to string?

Question

Given the following jq command and Json:

jq \'.[]|[.string,.number]|join(\": \")\' <<< \'
[
  {
    \"number\": 3,
    \"string\": \"threee\"
  },
          


        

Answer 1

The jq command has the tostring function. It took me a while to learn to use it by trial and error. Here is how to use it:

jq -r '.[] | [ .string, .number|tostring ] | join(": ")' <<< '
[{ "number": 9, "string": "nine"},
 { "number": 4, "string": "four"}]
'
nine: 9
four: 4

Answer 2

use 'map_values' opearator to modify objects

Example

{"foo": {"bar": 3}}

.foo.bar = .foo.bar|map_values(tostring)

Output

{ "foo": { "bar": "3" } }

Answer 3

An alternative and arguably more intuitive format is:

jq '.[] | .string + ": " + (.number|tostring)' <<< ...

Worth noting the need for parens around .number|tostring.

Answer 4

For such simple case string interpolation's implicit casting to string will do it:

.[] | "\( .string ): \( .number )"

See it in action on jq‣play.