What is the standard in JSON for differentiating between empty values and null values?

In the realm of programming, it is common practice to favor empty collections over null collections when there are zero elements. However, languages that interact with JSON, such as JavaScript, often interpret empty lists/objects as true and null ones as false. For instance, consider the following JSON object which would be deemed true and categorized as an object in JavaScript:

{
    "items_in_stock": {"widgets":10, "gadgets": 5}
}

Similarly, this JSON object would also be considered true:

{
    "items_in_stock": {}
}

On the other hand, this JSON object would be interpreted as false:

{
    "items_in_stock": null
}

Is there a standard convention regarding empty objects/lists in JSON? And how does this apply to numbers, booleans, and strings?

Answer №1

Best practice in programming dictates that when the expected return type is an array, it's better to return an empty array []. By doing this, the recipient of the json can easily handle the value as an array without needing to check for null first. The same principle applies to empty objects represented by open-closed braces {}.

For strings, booleans, and integers, there isn't a specific 'empty' form, so using null values for these types is acceptable.

Joshua Bloch covers this topic in his insightful book "Effective Java," where he discusses various beneficial generic programming practices that are often relevant to other programming languages. One such practice is returning empty collections instead of nulls.

If you're interested in learning more about this concept, check out this section in his book:

Answer №2

"Within JSON, there exists a unique value known as null which can be assigned to various types of data such as arrays, objects, numbers, and booleans."

"When it comes to the concept of empty within JSON, it specifically relates to arrays and objects...The idea of empty lists does not translate well with data objects, therefore no action is taken on those properties."

You can find more information here.

Answer №3

One thing to consider is whether we should distinguish between different cases:

  1. "phone" : "" = the value is empty

  2. "phone" : null = the value for "phone" was not set yet

If we choose to differentiate, using null would be the way to go. Otherwise, we might need to introduce a new field like "isAssigned" or similar. This issue has roots in legacy database systems.

Answer №4

An empty array is returned for collections that are empty, and the value null is returned for any other type of input.

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Eliminate the hover background color from the bootstrap nav-link

I've been struggling to eliminate the background color of the nav-link hover by setting it to transparent, but it still displays a background when hovered. I want to change the hover color for the text only, similar to the nav-brand, but I can't ...

jQuery: Remember to re-bind the form when it is returned successfully

Just a quick question: I'm currently using the jQuery.forms.js plugin. My situation involves a form that posts to a PHP page and receives data in JSON format. The returned data contains code for a new form, which replaces the original form used to s ...

Unravel various models in PHP Symfony by decoding JSON data into objects

Is there a way to effectively convert a multidimensional JSON into an object or model? When attempting to convert a JSON with nested structures, only the outer layer is successfully converted while inner layers remain as arrays. How can this issue be reso ...

Searching for JSON keys with corresponding JSON values in SQL Server

I currently have the following JSON data: Application 1: { "business_industry": "Agriculture", "docs": [ { "internal": false, "type": "Asset & Liability Statement" }, { ...

Creating a drop-down menu that aligns perfectly under the bar in Material-UI: What you need to know

While working with Material-UI, I encountered a problem with my drop-down menu. Every time I click on it, it covers the bar instead of appearing below it (see image links below). https://i.stack.imgur.com/1Y8CL.jpg https://i.stack.imgur.com/emf87.jpg Is ...

What is the best way to determine the midpoint index of an array?

As a newcomer, I have a question regarding a recent assignment. The task involves creating a global array where objects are imported as they are entered into an input field on the HTML document. The challenge is to update the current list on the document ...

Javascript challenges for beginners in coding world

After running the code snippet, I encountered the following error messages: at Module._compile (module.js:456:26) at Object.Module._extensions..js (module.js:474:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:312:12) at Fun ...

What alternatives are there to angular scope functions?

I find angular scope functions challenging to work with due to their lack of a clear contract. They extract parameters from the scope and store results back into the scope, rather than explicitly defining function parameters and returning a result. Conside ...

Is it possible to utilize THREE js ExtrudeGeometry to manipulate a shape along a jagged path?

Is it possible to use CatmullRomCurve3 to extrude over a sharp line, as shown in the image below: https://i.sstatic.net/wJNEv.png I am looking to achieve the following result: https://i.sstatic.net/Fe87K.png The goal is to achieve this with minimal pol ...

Tips for inserting items into an array of objects?

I have an array of objects with categories and corresponding points, and I need to calculate the total points for each category. { category: A, points:2 }, { category: A points: 3 }, { category: B, points: ...

What is the process for altering the active status in pagination?

How can I make the active class in my pagination appear in red? Here's the code snippet I have: In my script.js file: $(".pagination").append("<li class='page-item' id='previous-page'><a class='page-li ...

Monitoring the sequence of function calls within mock functions in Node.js

I am facing a challenge in writing an automated test that tracks the functions call chain. The scenario involves two functions, nativefn1 and nativefn2, where I cannot modify their code to enable tracking. I need to come up with a workaround for this situa ...

How can I retrieve one distinct document for each group based on a shared property value in MongoDB?

I have a database collection set up in MongoDB with a schema like this: var personSchema = new mongoose.Schema({ _id: ObjectId, name: String, // ... alias: String }; (I am using mongoose, but the details are not important). Because I retrieve pe ...

Using cakePHP to submit a form using ajax

While submitting a form using ajax and attempting to return a json response, I encountered an issue of receiving a missing view error. Adding autoResponder=false resulted in no response at all. This is happening while working with cakephp 2.5 In the same ...

Display the user's location on Google Maps in addition to all other markers for a comprehensive view

How can I modify the code to prompt the user for their location only when they click on a specific button, and then show all markers on the map? This jsfiddle illustrates the current issues: Google map loads markers from a database, and the user is asked b ...

dividing a solitary string (plain text only, no HTML) evenly among three separate div containers

Recently, I encountered a frustrating dilemma. I'm trying to split a string between three divs, but they are not equal in height, so I can't divide the string based on character count. To illustrate the issue, I've created a small sketch. ...

Having trouble rendering only half of a sphere in three.js

I'm currently working on a skydome project in three.js and here is how I am approaching it: var geometry = new THREE.SphereGeometry( 40, 32, 15, 1*Math.PI/2, 2*Math.PI, Math.PI, Math.PI); var material = new THREE.MeshBasicMaterial( { color: 0xddddff ...

Kubernetes is incorrectly marking the cron job as completed instead of displaying errors, despite the presence of errors

I am currently working on a cron job that will retrieve an excel file from an SFTP server and upload the data into a MongoDB database. In the event that there are errors in the cron job, such as a failure in the SFTP connection due to credential issues or ...

Developing client-side components with NextJS

I want to develop a single-page landing page where users can upload videos and there's a file size limit check before the upload. In my src/app/page.tsx file, I have the following code: import React from 'react'; import FileUpload from &apo ...

What methods can be used to prevent FireFox from continuously loading with a long-polling request?

Currently, I am implementing a long-polling request using the code snippet below (which is comparable to getJSON)... $.jsonp({ "url": url, "data": { "settings", settings }, "success": function(userProfile) { // handling user profile in ...