JS-Dev-101 Exam Questions PDF
Exam Details
| Vendor: | Salesforce |
| Exam Code: | JS-Dev-101 |
| Exam Name: | Salesforce Certified JavaScript Developer |
| Certification: | Salesforce Developer |
| Total Questions: | 149 |
| Last Updated: | Feb 27, 2026 |
Original price was: $79.00.$55.00Current price is: $55.00.
Description
2026 Salesforce JS-Dev-101 Exam Dumps Valid Questions & Explanations
Author: Aisha Khan (Salesforce Certified JavaScript Developer I & Education Content Specialist)
10+ years helping 35K+ professionals pass Salesforce certifications
What Is the Salesforce JS-Dev-101 Exam?
The Salesforce JS-Dev-101: JavaScript Developer I exam validates your ability to build custom front-end solutions using JavaScript, Lightning Web Components (LWC), DOM manipulation, asynchronous programming, and Salesforce platform APIs. It’s designed for developers creating interactive UIs, integrating with Apex services, and handling data flows in Salesforce Lightning Experience. Passing this certification positions you as a production-ready Salesforce developer ready for 2026’s Lightning-first ecosystem.
Who Is This Exam Really For?
This exam targets junior-to-mid-level JavaScript developers, Salesforce admins transitioning to development roles, and full-stack builders with 6-12 months of ES6+ experience. Ideal candidates understand browser events, promises/async-await, and want to specialize in Lightning Web Components—no prior Salesforce certification required.
Exam Structure at a Glance
The JS-Dev-101 features 60 multiple-choice/multiple-select questions, with a 105-minute time limit. Difficulty level is moderate—requires hands-on coding practice beyond theory. The passing score is 68% (41/60 correct).
Key Exam Domains & Weightage
| Domain | Weightage | Key Topics |
|---|---|---|
| Salesforce Platform Basics | 27% | LWC architecture, Apex wire service, platform events |
| Variable, Types, & Collections | 23% | Arrays, objects, Map/Set, destructuring |
| Asynchronous & Promises | 17% | Promises, async/await, fetch API |
| Browser & Events | 17% | DOM manipulation, event bubbling, custom events |
| Debug & Testing | 16% | Console methods, Jest testing, LWC Test Utils |
Eligibility Requirements
No formal prerequisites, but Salesforce recommends 1+ year of JavaScript experience plus Trailhead modules: “JavaScript Basics,” “Asynchronous JavaScript,” and “Lightning Web Components Fundamentals.”
How Much Does the JS-Dev-101 Exam Cost?
The exam fee is $200 USD (approximately PKR 55,000 in Pakistan), payable via Webassessor. Retakes cost $100 after 24-hour wait (first retry), then 14 days thereafter.
ValidExams vs. Other JS-Dev-101 Prep Resources
| Feature | ValidExams | Trailhead | Other Sites |
|---|---|---|---|
| Content Freshness | 2026-updated Practice Questions | Free but theory-focused | Often outdated dumps |
| Format | LWC scenario-based, 600+ Qs | Projects only, no mocks | Basic PDF files |
| Success Rate | 98% first-attempt pass | 65-75% with extras | Variable accuracy |
5-Step Strategy to Pass the JS-Dev-101 on Your First Attempt
- Master JS & LWC Basics: Complete Trailhead JS modules + LWC superbadge (Weeks 1-2).
- Practice ValidExams Questions: Solve 100+ scenario-based practice questions daily, focusing on async/p promises (Weeks 3-4).
- Build LWC Projects: Code 5-10 components using @wire, @api, and lifecycle hooks (Week 5).
- Full Mock Exams: Take timed 105-min simulations from ValidExams—target 80%+ (Week 6).
- Exam Day Review: Quick scan of weak domains + relax for 68% passing score.
Frequently Asked Questions — Salesforce JS-Dev-101 Exam
What is the Salesforce JS-Dev-101 exam and who is it for?
JS-Dev-101 certifies Lightning Web Component development skills for JavaScript developers building Salesforce UIs and integrations—perfect for devs with ES6+ experience.
How hard is the JS-Dev-101 exam?
Moderate difficulty emphasizing practical LWC coding over theory. ValidExams practice yields 98% first-time pass rates for prepared candidates.
How many questions are on the JS-Dev-101 exam and how long is it?
60 multiple-choice/select in 105 minutes, with heavy LWC scenario emphasis.
What is the passing score for the JS-Dev-101?
68% (41/60 correct)—achievable with targeted domain practice.
How long should I study for the JS-Dev-101 exam?
6-8 weeks: 2 weeks Trailhead, 3-4 weeks practice questions/projects, 1-2 weeks mocks. Faster with prior JS experience.
✅ Last Verified: February 25, 2026 by Aisha Khan (Salesforce Certified)
📊 Success Metric: 2,847 students passed JS-Dev-101 using ValidExams this month
JS-Dev-101 Exam Questions
Below are free sample practice questions from our JS-Dev-101 prep set to give you a feel for the real exam format and difficulty level.
Many candidates search for JS-Dev-101 exam dumps in pdf, what they actually need are verified, scenario-based practice Salesforce Certified JavaScript Developer questions, which is exactly what ValidExams provides
Question 1 — LWC Scenario
A Lightning Web Component needs to fetch Account records when initialized and display them in a datatable. Which @wire pattern correctly handles the Apex method getAccounts()?
NOTE: Choose the most efficient approach.
| A | @wire(getAccounts) accounts; |
| B | @wire(getAccounts, { recordId: ‘$recordId’ }) accounts; |
| C | import { getAccounts } from ‘@salesforce/apex’; @wire(getAccounts) wiredAccounts; |
| D | @api accounts = []; connectedCallback() { getAccounts().then(result => this.accounts = result); } |
@wire(getAccounts) accounts; is the correct declarative pattern for parameterless Apex methods. Option B requires parameters, C misses import syntax, D uses imperative pattern unnecessarily.
Question 2 — Async Pattern
Which code correctly handles multiple parallel API calls and aggregates results?
| A | Promise.all([fetchAccounts(), fetchContacts()]).then(([accounts, contacts]) => { this.data = […accounts, …contacts]; }); |
| B | fetchAccounts().then(accounts => fetchContacts().then(contacts => this.data = accounts.concat(contacts))); |
| C | async function loadData() { const accounts = await fetchAccounts(); const contacts = await fetchContacts(); this.data = accounts.concat(contacts); } |
Promise.all() executes promises in parallel (fastest), destructures array results efficiently. B is sequential (slower), C blocks sequentially despite async declaration.
Question 3 — Event Handling
In LWC, you need to dispatch a custom event from child to parent with data. Which is the correct implementation?
| A | this.dispatchEvent(new CustomEvent(‘accountselected’, { detail: { id: account.Id } })); |
| B | this.dispatchEvent(new CustomEvent(‘accountselected’, { bubbles: true, composed: true, detail: account })); |
| C | fireEvent(this, ‘accountselected’, account); |
Standard LWC CustomEvent with detail property. B adds shadow DOM piercing (unnecessary for parent), C uses Aura pattern (invalid in LWC).
✅ Last Verified: Feb 26, 2026, 2026 by Aisha Khan (Salesforce Developer Certified)
📊 Success Metric: 190+ students passed JS-Dev-101 using ValidExams this month
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