JavaScript-Developer-I Salesforce Certified JavaScript Developer (JS-Dev-101) Free Practice Exam Questions (2025 Updated)

developer publishes a new version of a package with new features that do not break

backward compatibility. The previous version number was 1.1.3.

Following semantic versioning format, what should the new package version number

be?

A developer needs to debug a Node.js web server because a runtime error keeps occurring at one of the endpoints.

The developer wants to test the endpoint on a local machine and make the request against a local server to look at the behavior. In the source code, the server, js file will start the server. the developer wants to debug the Node.js server only using the terminal.

Which command can the developer use to open the CLI debugger in their current terminal window?

Which code change should be done for the console to log the following when 'Click me!' is clicked'

> Row log

> Table log

At Universal Containers, every team has its own way of copying JavaScript objects. The

code

Snippet shows an implementation from one team:

Function Person() {

this.firstName = “John”;

this.lastName = ‘Doe’;

This.name =() => (

console.log(‘Hello $(this.firstName) $(this.firstName)’);

)}

Const john = new Person ();

Const dan =JSON.parse(JSON.stringify(john));

dan.firstName =’Dan’;

dan.name();

What is the Output of the code execution?

Which code statement below correctly persists an objects inlocal Storage ?

Universal Containers recently launched its new landing page to host a crowd-funding

campaign. The page uses an external library to display some third-party ads. Once the page is

fully loaded, it creates more than 50 new HTML items placed randomly insidethe DOM, like the

one in the code below:

All the elements includes the same ad-library-item class, They are hidden by default, and they are randomly displayed while the user navigates through the page.

Given the JavaScript below:

Which code should replace the placeholder comment on line 06 to hide accounts that do not match the search string?

Refer to code below:

Const objBook = {

Title: ‘Javascript’,

};

Object.preventExtensions(objBook);

Const newObjBook = objBook;

newObjectBook.author =‘Robert’;

What are the values of objBook and newObjBook respectively ?

Given the HTML below:

Which statement adds the priority-account css class to the Applied Shipping row?

Refer to the code below:

Let inArray =[ [ 1, 2 ] , [ 3, 4, 5 ] ];

Which two statements result in the array [1, 2, 3, 4, 5] ?

Choose 2 answers

Given the code below:

const delay = sync delay => {

Return new Promise((resolve, reject) => {

setTimeout (resolve,delay);});};

const callDelay =async () =>{

const yup =await delay(1000);

console.log(1);

What is logged to the console?

A developer is required to write a function that calculates the sum of elements in an

array but is getting undefined every time the code is executed. The developer needs to find

what is missing in the code below.

Const sumFunction = arr => {

Return arr.reduce((result, current) => {

//

Result += current;

//

), 10);

);

Which option makes the code work as expected?

Which code statement correctly retrieves and returns an object from localStorage?

Which statement accurately describes an aspect of promises?

Refer to the code below:

let timeFunction =() => {

console.log(‘Timer called.”);

};

let timerId = setTimeout (timedFunction, 1000);

Which statement allows a developer to cancel the scheduled timed function?

Consider type coercion, what does the following expression evaluate to?

True + 3 + ‘100’ + null

Refer to HTML below:

Which expression outputs the screen width of the element with the ID card-01?

Which two console logs outputs NaN ?

Choose 2 answers

A developer wants to iterate through an array of objects and count the objects and count

the objects whose property value, name, starts with the letterN.

Const arrObj = [{“name” : “Zach”} , {“name” : “Kate”},{“name” : “Alise”},{“name” : “Bob”},{“name” :

“Natham”},{“name” : “nathaniel”}

Refer to the code snippet below:

01 arrObj.reduce(( acc, curr) => {

02 //missing line 02

02 //missing line 03

04 ). 0);

Which missing lines 02 and 03 return the correct count?