jq for JSON

By  on  

I old enough to remember when we thought XML was going to change the programming world...then JSON saved us from that hell. Parsing and querying JSON data is fundamental task we've all coded for, but sometimes I just want to get some data locally with minimal fuss. I just learned of a really awesome library to do so: jq. Let's have a look at some cool things we can do with jq!

Start by installing jq via a utility like Homebrew:

brew install jq

With Homebrew installed and a local actors.json file, let's go to work on pulling some data!

// Using this JSON file:
// https://raw.githubusercontent.com/algolia/datasets/master/movies/actors.json

// Get the 10th item in an array
cat actors.json | jq '.[10]'
// {
//   "name": "Dwayne Johnson",
//   "rating": 1568,
//   "image_path": "/akweMz59qsSoPUJYe7QpjAc2rQp.jpg",
//   "alternative_name": "The Rock",
//   "objectID": "551486400"
// }

// Get a property from the 10th item in array
// > "Dwayne Johnson"

// Get multiple items
jq '.[10:12]'

// Get items up to the 12th position
jq '.[:12]'

// Get items after the 12th position
jq '.[12:]'

// Get an array of properties from all objects
jq '.[].name'
// > ["William Shatner", "Will Ferrell", ...]

// Create an object with only properties I want
jq '{ name: .[].name, rating: .[].rating}'

// Built in functions!
jq 'sort'
jq 'length'
jq 'reverse'

There are loads of other ways to use jq, so I highly recommend you check out JQ Select Explained: Selecting elements from JSON. I'll keep jq handy for the foreseeable future, as it will be invaluable!

Recent Features

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

  • By
    Responsive and Infinitely Scalable JS Animations

    Back in late 2012 it was not easy to find open source projects using requestAnimationFrame() - this is the hook that allows Javascript code to synchronize with a web browser's native paint loop. Animations using this method can run at 60 fps and deliver fantastic...

Incredible Demos

  • By
    CSS Circles

    A while back I shared a clever technique for creating triangles with only CSS. Over the past year, I've found CSS triangles incredibly effective, especially when looking to create tooltips or design elements with a likewise pointer pattern. There's another common shape...

  • By
    Fading Links Using jQuery:  dwFadingLinks

    UPDATE: The jQuery website was down today which caused some issues with my example. I've made everything local and now the example works. Earlier this week, I posted a MooTools script that faded links to and from a color during the mouseover and mouseout events.

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!