1. Home
  2. Salesforce
  3. JS-Dev-101 Exam Info
  4. JS-Dev-101 Exam Questions

Salesforce JS-Dev-101 Actual Exam Questions - Instant Access

Breaking into elite Salesforce development roles demands more than ambition—it requires proven JavaScript mastery that employers trust. Our JS-Dev-101 practice materials transform anxious candidates into confident professionals ready to tackle asynchronous programming, Lightning Web Components, and modern ES6+ challenges. With over 12,000 developers already certified using our three flexible formats—PDF for on-the-go studying, web-based for instant access anywhere, and desktop software for distraction-free deep practice—you're joining a community that understands the pressure of certification deadlines. Each question mirrors real exam scenarios, covering DOM manipulation, testing frameworks, and Salesforce platform integration that hiring managers actively seek. Whether you're targeting Lightning Developer positions, full-stack Salesforce roles, or consulting opportunities with six-figure potential, these materials compress months of preparation into focused, efficient study sessions. Stop second-guessing your readiness—experience the same preparation method that's helped thousands pass on their first attempt.

Page: 1 /
Total 147 questions
Unlock 147 Premium Questions Get Free Questions & Answers PDF
Question 1

Refer to the code below:

01 funetion Person() (

02 thie. fixsttane = "Zoha'y

os}

05 Perscn.prototype = [

06 jek: x => 'Developer'

onde

09 const myFather = new Peracn():

10 const result = myFather.firstiame + ' * + myFather.jeb()

What is the value of result after line 10 executes?


Correct : A


Options Selected by Other Users:
Mark Question:

Start a Discussions

Submit Your Answer:
0 / 1500
Question 2

01 class Student {

02 constructor(name) {

03 this._name = name;

04 }

05 displayGrade() {

06 console.log(`${this._name} got 70% on test.`);

07 }

08 }

09

10 class GraduateStudent extends Student {

11 constructor(name) {

12 super(name);

13 this._name = "Graduate Student " + name;

14 }

15 displayGrade() {

16 console.log(`${this._name} got 100% on test.`);

17 }

18 }

19 let student = new GraduateStudent("Jane");

20 student.displayGrade();

```

What is the console output?:


Correct : C


Options Selected by Other Users:
Mark Question:

Start a Discussions

Submit Your Answer:
0 / 1500
Question 3

A developer wants to use a module named universalContainerslib and then call functions from it. How should a developer import every function from the module and then call the functions foo and bar?


Correct : A

import * as lib from '...' imports all named exports from the module into the namespace object lib.

You then call:

lib.foo();

lib.bar();

Option D correctly imports only foo and bar, not every function. The question explicitly says ''import every function... and then call foo and bar'', so A best matches.

Options B and C are invalid syntax or reference the wrong identifier.

________________________________________


Options Selected by Other Users:
Mark Question:

Start a Discussions

Submit Your Answer:
0 / 1500
Question 4

01 function Monster() { this.name = 'hello'; };

02 const m = Monster();

What happens due to the missing new keyword?


Correct : B

________________________________________

Comprehensive and Detailed Explanation From Exact Extract JavaScript Knowledge

In JavaScript, when calling a constructor function without new:

const m = Monster();

the following happens:

The function executes as a normal function, not as a constructor.

Inside a regular function (in non-strict mode), this refers to the global object:

In a browser: window

So the line:

this.name = 'hello';

becomes:

window.name = 'hello';

Since Monster() does not return anything, its return value is undefined:

const m = undefined;

Therefore:

m is undefined

window.name becomes 'hello'

This matches option B.

________________________________________

JavaScript Knowledge Reference (text-only)

Calling a function without new uses the global object as this in non-strict mode.

Constructor functions must use new to create a new object.

Functions without an explicit return return undefined.


Options Selected by Other Users:
Mark Question:

Start a Discussions

Submit Your Answer:
0 / 1500
Question 5

Refer to the code below:

01 let timedFunction = () => {

02 console.log('Timer called.');

03 };

04

05 let timerId = setInterval(timedFunction, 1000);

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


Correct : A

Comprehensive and Detailed Explanation From JavaScript Knowledge:

The code:

let timerId = setInterval(timedFunction, 1000);

setInterval schedules timedFunction to run every 1000 ms.

It returns an interval ID (here stored in timerId), which is used to cancel the interval later.

To cancel:

Use clearInterval(timerId);

This is the standard browser (and Node.js) API:

let id = setInterval(fn, delay);

clearInterval(id); stops future executions of that interval.

Check other options:

B . removeInterval(timerId);

There is no removeInterval function in the standard JavaScript timer API.

C . removeInterval(timedFunction);

Again, no such function; and timers are cancelled by ID, not by the callback function reference.

D . clearInterval(timedFunction);

clearInterval expects the ID returned by setInterval, not the callback function.

Passing the function does not cancel the timer.

Therefore, the correct statement is:

Answe r: A

Study Guide / Concept Reference (no links):

Timer APIs: setInterval and clearInterval

Relationship between timer ID and cancellation

Difference between interval ID and callback function

Basic async timing patterns in JavaScript


Options Selected by Other Users:
Mark Question:

Start a Discussions

Submit Your Answer:
0 / 1500
Page:    1 / 30   
Total 147 questions