How to convert a string to an integer in a JSON file using jq?

Question

I use jq to transform a complex json object into a tinier one. My query is:

jq 'to_entries[]| {companyId: (.key), companyTitle: (.value.title), companyCode: (.value.booking_service_code)}' companies.json

Now, the (.key) is parsed as a string, yet I want companyId to be a number.

My result currently looks like this:

{
  "companyId": "1337",
  "companyTitle": "Some company title",
  "companyCode": "oxo"
}

yet it should be like:

{
  "companyId": 1337,
  "companyTitle": "Some company title",
  "companyCode": "oxo"
}

k0pernikus · Accepted Answer · 2019-01-28 11:44:42Z

92

jq has inbuilt functions, you can pipe your key to tonumber:

jq 'to_entries[]| {companyId: (.key)|tonumber, companyTitle: (.value.title), companyCode: (.value.booking_service_code)}' companies.json

As per the docs:

tonumber The tonumber function parses its input as a number. It will convert correctly-formatted strings to their numeric equivalent, leave numbers alone, and give an error on all other input.

Example jq '.[] | tonumber' Input [1, "1"] Output 1 1

edited Jan 28, 2019 at 11:44

answered Feb 20, 2018 at 14:38

k0pernikus

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2 Comments

Canovice Over a year ago

Anyway to do this while somehow handling null values?

k0pernikus Over a year ago

@Canovice Please open a new question with that requirement. You can link this answer there.

Greg · Accepted Answer · 2020-09-25 14:41:25Z

10

I was trying to turn my string (that converts to a float) to an integer. I was looking for a 'toint' function, one doesn't exist.

jq --arg str "1.435" -n '$str|tonumber'
1.435

I threw a floor in there to make sure the number that was created was an integer:

jq --arg str "1.435" -n '$str|tonumber|floor'
1

This also properly converts the OP original data as well. If you want to guarantee your result is an integer you will need to floor it.

answered Sep 25, 2020 at 14:41

Greg

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2 Comments

peak Over a year ago

Or perhaps round.

bfontaine May 9 at 14:29

For anyone wondering why there is no toint function, this is because there’s no such thing as integers or floats in JSON, there are only "numbers", like in JS.

Ramon Fincken · Accepted Answer · 2024-05-11 09:57:27Z

2

Warning: using tonumber WILL remove any prefixed zeros like: "data":{"order_number":"024058275" => 24058275

use sed ( or awk ) to remove the ' " '

echo $result | jq '.data.order_number' | sed 's|["]||g'

This will return 024058275

answered May 11, 2024 at 9:57

Ramon Fincken

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1 Comment

bfontaine May 9 at 14:30

["] can be shortenen as "

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