What is the process for implementing optional chaining on a JSON object?

I'm currently facing an issue where I need to compare a value within a JSON object with a variable.

if (resp.userdetails.name == username) {
// do something
}

The challenge arises when not all resp objects contain the userdetails property, resulting in occasional error messages like:

Cannot read properties of undefined (reading 'name')

I've attempted using the optional chaining operator ? to account for its potential absence:

if (resp.userdetails?.name == username)

However, this leads to an Unexpected token error in my code.

Is there a way to modify my if statement to indicate that userdetails may not always be present in the response but should be checked for when it is, and then verify that name matches username?

Answer №1

To address this issue, you can take any of the following measures:

  • Utilize a JavaScript engine that offers support for optional chaining. For more information on browser compatibility, refer to this link
  • Employ a tool like Babel to transpile your modern JS code into an older version without optional chaining
  • Check manually if the object exists before attempting to access its properties
if (resp.userdetails && resp.userdetails.name == username)

Answer №2

If you have integrated lodash in your project, you can access the data using

_.get(resp,"userdetails.name")

as per the official documentation.

In case lodash is not yet part of your project dependencies, I highly recommend installing it from npm as it is considered one of the most versatile and widely used utility packages available.

Answer №3

Lodash stands out as a widely-used JavaScript library that offers over 200 functions to streamline web development processes. From map and filter to function binding, template creation, deep equality checks, and index generation, Lodash caters to various needs in web development. Moreover, it seamlessly integrates with both browsers and Node.js environments.

Manipulating objects in JavaScript can be intricate, especially when dealing with extensive modifications. With its array of features, Lodash simplifies object manipulation tasks effectively.

Being an open-source project, Lodash allows easy contribution from users. You can extend the library by adding plugins and sharing them on GitHub or through Node.js.

Syntax

_.get(object, path, [defaultValue]) retrieves the value at the specified path within an object. In case the resolved value is undefined, the defaultValue takes its place.

Arguments

object (Object) − The object to be queried.

path (Array|string) − The property's path to retrieve.

[defaultValue] (*) − The value to return for unresolved values.

If you have integrated lodash into your project, utilize the following:

_.get(resp,"userdetails.name")

as mentioned in the documentation.

If you haven't yet added lodash, I recommend installing it via npm, as it remains the top choice among utility packages.

Use the command below to install Lodash:

npm install loadash

https://i.sstatic.net/z2tQo.png Example:

var _ = require("lodash");

var data = [
  { userdetails: { name: "d" } },
  {},
  { userdetails: {} },
  { userdetails: { name: "d" } },
];

for (i = 0; i < data.length; i++) {
  var resp = data[i];
  if (_.get(resp, "userdetails.name") == "d") {
    //   if (resp.userdetails && resp.userdetails.name == "d") {    use without loadlash
    console.log("Success");
  } else {
    console.log("failed");
  }
}

Although using lodash may seem complex at first, it effectively prevents runtime errors. The following expressions yield the same outcome:

resp.userdetails && resp.userdetails.name == "d"

                        ===

         _.get(resp, "userdetails.name") == "d"

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

Guide on setting a property for req.session

I'm a beginner in node.js and sessions, and I am having trouble setting properties to the session! I am trying to add a property to the session and save it in the database, but I keep getting errors. Here are my codes: app.js (main js file) const s ...

Troubleshooting overlap problem between Skrollr and SlickNav

I successfully implemented Skrollr to fix images, similar to this example: Additionally, I am utilizing Slicknav for the menu functionality. However, I encountered an issue where the menu opens behind the fixed "parallax" image. Despite trying various ap ...

What is the best way to create a visual separation between these two arrows using styled-components?

Currently, I am immersing myself in styled-components and attempting to replicate the image provided below. Although I can achieve this with CSS, I am solely focusing on utilizing styled components for this task. <Container> {sliderItems.map((item) ...

Pause execution of javascript function for a short period

When the button is clicked, my script executes the function manage($n) $onclick = "manage('$n');"; However, I also want to refresh the page immediately after it is clicked. $onclick="window.location.reload(true);manage('$n')"; Altho ...

The loading indicator fails to show up when users navigate between pages that have already been loaded in NextJS and ReactJS

What do I need: I am seeking a way to show a loading indicator whenever a user switches between pages on my website. After discovering an effective example at https://github.com/zeit/next.js/tree/canary/examples/with-loading, I implemented a similar appro ...

Effortlessly add and manipulate multiple classes in a generic class using querySelectorAll and classList, eliminating the

I'm encountering an issue that requires me to repeatedly utilize querySelectorAll with Element.classList. Each time, I must convert the NodeList obtained from Element.querySelectorAll into an Array. Then, I need to iterate over the Array using a for ...

What is the method to select a hyperlink that includes a variable in the "href" attribute and click on it?

Currently, I am in the process of creating acceptance tests utilizing Selenium and WebdriverIO. However, I have encountered a problem where I am unable to successfully click on a specific link. client.click('a[href=#admin/'+ transactionId + &apo ...

Angular movie database using an API from an apiary

I'm struggling to create a link on movie posters that will lead to detailed movie information based on the movie ID. I have been going through their documentation, but I can't seem to get the api configuration to function properly. Every time I t ...

Unable to locate module within a subdirectory in typescript

The issue I'm facing involves the module arrayGenerator.ts which is located in a subfolder. It works perfectly fine with other modules like Array.ts in the parent folder. However, when I introduced a new module called Sorting.ts, it started giving me ...

Pondering in AngularJS - what is the best way to alter the DOM during an AJAX call?

I'm completely new to AngularJS and trying to transition from a jQuery background. After reading through "Thinking in AngularJS if I have a jQuery background?" on Stack Overflow, I understand the concept but am struggling to implement it without depen ...

AddRegions does not function as expected

Basic code to initialize an App define(['marionette'],function (Marionette) { var MyApp = new Backbone.Marionette.Application(); MyApp.addInitializer(function(options) { // Add initialization logic here ...

The dynamic value feature in Material UI React's MenuItem is currently experiencing functionality issues

Whenever I use Select in Material UI for React, I encounter an issue where I always receive undefined when selecting from the drop-down menu. This problem seems to occur specifically when utilizing dynamic values with the MenuItem component. If I switch to ...

Expansive menu that stretches the full height of the webpage

I'm having difficulty making my side spry menu extend the full length of the webpage. I tried using this code: $("nav").css({ "height" : $("nav").height() }); but it still isn't working as expected. I just want the grey color, like ...

Ways to handle Sessions in Node.js

I'm attempting to utilize a website within node.js. However, the site is prompting me to enable the storage of session cookies. I attempted to set up a cookie-jar, but I couldn't get it to work. Here is a simplified version of the code that is c ...

Expanding functionality: Steps to integrating a new endpoint into your AWS Amplify Express Server

I have created a REST express server using Amplify. Attempted to include two additional endpoints: // incorporating serverless express app.post('/myendpoint', function(req, res) { console.log('body: ', req.body) res.json(req.body) ...

Iterating Through Array with Node JS Before Adding a New Property

There is a JSON input with data connected to a secondary model called Users. To process this, I need to iterate through listingData.Agents to extract the index ID and then use this ID to find the corresponding user. The challenge here is that due to asynch ...

JSON payload with an array that includes nested JSON objects

I am struggling with JSON objects and need to create a JSN structure similar to the following: { name: 'root', children: [ name: 'son1', children: [....] ] } Could someone please guide me on how to construct it using Java ...

Nock is capturing my request, however, my AJAX call is encountering an error

I am currently conducting a test on an AJAX request using the XMLHttpRequest method: export default function performTestRequest() { const xhr = new XMLHttpRequest(); xhr.open('GET', 'https://example.com/service'); xhr.onload = ( ...

Operating on a duplicate of the array is necessary for mapping an array of objects to function properly

I'm starting to uncover a mysterious aspect of Javascript that has eluded me thus far. Recently, I've been pulling an array of objects from a database using Sequelize. This array is quite intricate, with several associations included. Here' ...

You are unable to define a module within an NgModule since it is not included in the current Angular compilation

Something strange is happening here as I am encountering an error message stating 'Cannot declare 'FormsModule' in an NgModule as it's not a part of the current compilation' when trying to import 'FormsModule' and 'R ...