Is there a way to shuffle json value-pair's

Question

I have a set of key-value pairs in which there are url's of images and this json file is saved in the realtime database of firebase.My question is can we reorder the values(url's) after exporting the json in desktop and opening in notepad++? or is there any other way?

If we can reorder the values like in this example the alone pair have 3 url's and if we can reorder them such a way that the first one becomes third and second one becomes first then the end user on the application can see the photo in different order every time we change/reorder/shuffle url's in database. As there are only three url's given for alone it's easy for us and we can do it manually and it's not time consuming, just imagine that the alone pair is having 100 url's then it's difficult to change manually each url as it's time consuming and a lot more confusing

An example of json file is-

{
  "URLs" : {
    "ALONE" : [ "https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/alone.jpg?alt=media&token=1f8ee2bd-7bd2-4223-b708-2ae48ab3c5da", "https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/6094594.jpg?alt=media&token=2c2611af-6e15-4d8e-8d4e-32fa347d8025", "https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/8620007.jpg?alt=media&token=c54ec2ff-8c15-41ba-b0f1-e9d256586ce2",],
    "AMAZING" : [ "https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/amazing.jpg?alt=media&token=381900b3-cab9-4802-a9db-6d8b938d3d16", "https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/7514001.jpg?alt=media&token=1e424124-103f-4bbe-b28d-736896d3afe4", "https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/4546211.jpg?alt=media&token=35fbf774-4262-4c45-8e7d-8efbaafabd29",],
  }
}

P.S.- This is just an example file so only a few is given the actual file is too big to just shuffle it manually in notepad++

What exactly do you mean by "shuffle"? Could you edit the question to better illustrate what you'd like to see happen? — Doug Stevenson, Nov 25 '19 at 17:21
You've shown one JSON snippet, but not yet what you want it to become. Also note that it would really help to see what you've already tried. — Frank van Puffelen, Nov 25 '19 at 18:19

score 0 · Answer 1 · answered Nov 25 '19 at 17:49

0

The order of keys in a JSON object is by definition undefined. So while you can reorder the lines in the text file that you export, that does not necessarily affect the JSON object when the file is parsed again.

answered Nov 25 '19 at 17:49

Frank van Puffelen

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Yes, but the actual file contains a lot of lines and It would take a really long time to reorder it. – Hiddleston Chris Nov 25 '19 at 18:06

Renaud Tarnec · Answer 2 · 2019-11-25T22:55:03.633

0

I understand that you want to shuffle the arrays in order to display the pictures in a different order each time.

You will find in this SO question different methods to shuffle an array.

The following code will shuffle each array of the URLs object.

  function shuffleArray(array) {
    for (let i = array.length - 1; i > 0; i--) {
      const j = Math.floor(Math.random() * (i + 1));
      [array[i], array[j]] = [array[j], array[i]];
    }
    return array;
  }

  const rawObj = {
    URLs: {
      ALONE: [
        'https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/alone.jpg?alt=media&token=1f8ee2bd-7bd2-4223-b708-2ae48ab3c5da',
        'https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/6094594.jpg?alt=media&token=2c2611af-6e15-4d8e-8d4e-32fa347d8025',
        'https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/8620007.jpg?alt=media&token=c54ec2ff-8c15-41ba-b0f1-e9d256586ce2'
      ],
      AMAZING: [
        'https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/amazing.jpg?alt=media&token=381900b3-cab9-4802-a9db-6d8b938d3d16',
        'https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/7514001.jpg?alt=media&token=1e424124-103f-4bbe-b28d-736896d3afe4',
        'https://firebasestorage.googleapis.com/v0/b/simple-motivation.appspot.com/o/4546211.jpg?alt=media&token=35fbf774-4262-4c45-8e7d-8efbaafabd29'
      ]
    }
  };

  const urlsObj = rawObj.URLs;
  const keys = Object.keys(urlsObj);
  for (const key of keys) {
    console.log(urlsObj[key]);
    console.log(shuffleArray(urlsObj[key]));
  }

If you want the shuffling to be applied to all the elements of all the arrays, you could do as follows:

  function shuffleArray(array) {
    //.....
    return array;
  }

  const rawObj = {...};

  const urlsObj = rawObj.URLs;
  const keys = Object.keys(urlsObj);

  let fullArray = [];
  for (const key of keys) {
    fullArray = fullArray.concat(urlsObj[key]);
  }
  console.log(fullArray);
  console.log(shuffleArray(fullArray));

edited Nov 25 '19 at 22:55

answered Nov 25 '19 at 22:34

Renaud Tarnec

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On which IDE i should run this? – Hiddleston Chris Nov 26 '19 at 16:24
This is just JavaScript code. So you may execute it in your front-end (if it's a web app) or you could execute it in a Cloud Function. – Renaud Tarnec Nov 26 '19 at 16:47
So should I run this through notepad++ ?? because it's in the realtime database and I can't put the code in the real time database to run it automatically. – Hiddleston Chris Nov 29 '19 at 07:17
It all depends if you want to do that once or each time a user query the list of images. – Renaud Tarnec Nov 29 '19 at 08:49
How can I add this program in the realtime database of firebase? – Hiddleston Chris Nov 29 '19 at 11:54
It depends on how you read the Realtime database. Do you read it from a client (an app)? Or from a server? – Renaud Tarnec Nov 29 '19 at 12:02
The images uploaded to realtime database are been shown in the app for the users. – Hiddleston Chris Nov 29 '19 at 12:11
So if you app is a web app, you can use the JavaScript code in the answer to shuffle the images before displaying them, on the client side. – Renaud Tarnec Nov 30 '19 at 09:22
The app is an android application for android phones which uses firebase realtime database as a backend.So where should I add the above code?IN the realtime database there are four options-data,rules,backup and usage. – Hiddleston Chris Nov 30 '19 at 16:18

Is there a way to shuffle json value-pair's

2 Answers2