The Salesforce JS-Dev-101 - Salesforce Certified JavaScript Developer exam is designed for candidates pursuing the Salesforce Developer certification path. It validates practical JavaScript knowledge that is relevant to building modern solutions in Salesforce-focused environments. This exam matters because it helps confirm that you can apply core JavaScript skills in real development scenarios with confidence.
Whether you are preparing to grow your Salesforce development profile or strengthen your JavaScript foundation, this certification is aimed at learners who want to prove job-ready coding ability. A solid understanding of the exam structure and topic coverage can make your preparation more focused and efficient.
| # | Exam Topics | Sub-Topics | Approximate Weightage (%) |
|---|---|---|---|
| 1 | Variables, Types, and Collections | Variable declarations, primitive types, arrays, maps and sets | 18% |
| 2 | Objects, Functions, and Classes | Object literals, function scope, class syntax, inheritance basics | 18% |
| 3 | Browser and Events | DOM access, event listeners, event propagation, browser APIs | 15% |
| 4 | Debugging and Error Handling | Console tools, breakpoints, try-catch, throwing errors | 12% |
| 5 | Asynchronous Programming | Promises, async and await, callbacks, event loop basics | 18% |
| 6 | Server Side JavaScript | Runtime concepts, modules, server interactions, data handling | 11% |
| 7 | Testing | Unit tests, assertions, test cases, code validation | 8% |
This exam tests more than memorization. It checks your understanding of JavaScript concepts, your ability to read and reason about code, and your practical skill in choosing the right solution for common development tasks. Candidates should expect questions that measure accuracy, troubleshooting ability, and familiarity with modern JavaScript patterns.
QA4Exam.com provides Exam PDF content with actual questions and answers, plus an Online Practice Test that helps you prepare with confidence for the Salesforce JS-Dev-101 exam. The practice format gives you a real exam simulation so you can understand the question style and improve your speed.
You also get up-to-date questions, verified answers, and a focused way to review the exam topics without wasting time on irrelevant material. By practicing under timed conditions, you can improve time management and reduce surprises on exam day.
This combination makes it easier to build confidence and aim for a first-attempt pass.
This exam is for candidates pursuing the Salesforce Developer certification path and want to validate JavaScript skills relevant to Salesforce development.
It can be challenging because it checks both theory and practical understanding of JavaScript topics such as asynchronous programming, debugging, and testing.
Braindumps alone are not the best approach. You should use them with practice and review so you understand why the answers are correct and can handle new question patterns.
Hands-on experience is very helpful because this exam focuses on practical JavaScript knowledge and code-based problem solving.
The QA4Exam.com Exam PDF and Online Practice Test are strong preparation tools, especially when you want verified answers and realistic practice, but studying the topic list and understanding the concepts will improve your results further.
They help you learn the question style, practice under time pressure, and review correct answers before the exam, which can improve confidence and readiness for a first attempt.
QA4Exam.com offers an Exam PDF with actual questions and answers and an Online Practice Test that simulates the exam experience.
static delay = async delay => {
return new Promise(resolve => {
setTimeout(resolve, delay);
});
};
static asyncCall = async () => {
await delay(1000);
console.log(1);
};
console.log(2);
asyncCall();
console.log(3);
Assume delay and asyncCall are in scope as functions.
What is logged to the console?
The correct answer is D, because JavaScript executes synchronous code first, while the code after await runs later after the Promise resolves.
The execution order is:
console.log(2);
This runs first, so JavaScript logs:
2
Then this line runs:
asyncCall();
The asyncCall() function starts executing. Inside it, JavaScript reaches:
await delay(1000);
The delay(1000) function returns a Promise that resolves after 1000 milliseconds:
return new Promise(resolve => {
setTimeout(resolve, delay);
});
Because await pauses the rest of the asyncCall() function, this line does not run immediately:
console.log(1);
Instead, JavaScript continues executing the remaining synchronous code outside the async function:
console.log(3);
So JavaScript logs:
3
After approximately 1000 milliseconds, the Promise returned by delay(1000) resolves. Then the paused async function continues and runs:
console.log(1);
So JavaScript logs:
1
Final console output:
2
3
1
Important JavaScript concepts involved:
An async function always returns a Promise.
The await keyword pauses execution only inside the async function where it appears.
Code outside the async function continues running normally.
setTimeout() schedules its callback to run later, after the current synchronous code has finished.
Therefore, the verified answer is D. 2 3 1.
Refer to the code below:
01 let first = 'Who';
02 let second = 'What';
03 try {
04 try {
05 throw new Error('Sad trombone');
06 } catch (err) {
07 first = 'Why';
08 throw err;
09 } finally {
10 second = 'When';
11 }
12 } catch (err) {
13 second = 'Where';
14 }
What are the values for first and second once the code executes?
Initial values:
first = 'Who'
second = 'What'
Execution:
Inner try/catch/finally:
Line 05: throw new Error('Sad trombone');
Control goes to the inner catch.
Inner catch (lines 06--08):
catch (err) {
first = 'Why';
throw err;
}
first is set to 'Why'.
The error is rethrown.
Inner finally (lines 09--11):
finally {
second = 'When';
}
finally runs whether or not there was an error.
second becomes 'When'.
After inner finally, the rethrown error continues to propagate to the outer catch.
Outer catch (lines 12--14):
} catch (err) {
second = 'Where';
}
Because the inner try rethrew, the outer catch runs.
It sets second = 'Where'.
Final values:
first was changed to 'Why' in the inner catch and never changed again.
second became 'When' in the inner finally, and then 'Where' in the outer catch.
So:
first is 'Why'
second is 'Where'
Option B is correct.
Concepts: nested try/catch/finally, rethrowing errors, order of execution for catch vs finally, variable mutation through error propagation.
Refer to the following code block:
01 let array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];
02 let output = 0;
03
04 for (let num of array) {
05 if (output > 10) {
06 break;
07 }
08 if (num % 2 == 0) {
09 continue;
10 }
11 output += num;
12 }
What is the value of output after the code executes?
This code uses:
A for...of loop to iterate over values in array.
break to exit the loop entirely when output > 10.
continue to skip even numbers.
It sums only certain numbers into output.
Let's walk through the loop step by step.
Initial values:
array = [1,2,3,4,5,6,7,8,9,10,11]
output = 0
Loop: for (let num of array) { ... }
First iteration: num = 1
Line 05: if (output > 10) 0 > 10 is false no break.
Line 08: if (num % 2 == 0) 1 % 2 == 1, not 0, so false no continue.
Line 11: output += num output = 0 + 1 = 1.
Second iteration: num = 2
output > 10 1 > 10 is false no break.
num % 2 == 0 2 % 2 == 0, so true continue.
Because of continue, line 11 is skipped.
output remains 1.
Third iteration: num = 3
output > 10 1 > 10 is false.
num % 2 == 0 3 % 2 == 1, false no continue.
output += num output = 1 + 3 = 4.
Fourth iteration: num = 4
output > 10 4 > 10 is false.
num % 2 == 0 4 % 2 == 0, true continue.
Skip sum; output remains 4.
Fifth iteration: num = 5
output > 10 4 > 10 is false.
num % 2 == 0 5 % 2 == 1, false.
output += num output = 4 + 5 = 9.
Sixth iteration: num = 6
output > 10 9 > 10 is false.
num % 2 == 0 6 % 2 == 0, true continue.
output remains 9.
Seventh iteration: num = 7
output > 10 9 > 10 is false.
num % 2 == 0 7 % 2 == 1, false.
output += num output = 9 + 7 = 16.
Eighth iteration would be num = 8, but:
At the top of the loop body, line 05 is checked again:
if (output > 10) 16 > 10 is true, so break; is executed.
When break runs:
The loop terminates immediately.
No further iterations (for num = 8, 9, 10, 11) are executed.
Therefore, output stays at 16.
Final value of output after the loop ends is 16.
This matches option A.
Why other options do not match:
B . 25: Would require adding more odd numbers (e.g., 9, 11) after 7, but the loop stops early due to output > 10.
C . 11: Would be smaller; the actual sum of 1 + 3 + 5 + 7 until break is 16.
D . 36: Would require summing many more values (e.g., most or all odd numbers up to 11), but again, the break condition stops the loop once output exceeds 10.
So:
Answe r: A
JavaScript knowledge / Study Guide references (concept names only, no links):
for...of loop over arrays
break statement in loops (terminating a loop early)
continue statement in loops (skipping to the next iteration)
Modulo operator % to test even and odd numbers
Step-by-step execution and control flow in loops
Refer to the code:
01 console.log('Start');
02 Promise.resolve('Success').then(function(value) {
03 console.log('Success');
04 });
05 console.log('End');
What is the output after the code executes successfully?
console.log('Start') runs immediately (synchronous).
Promise.resolve().then(...) places the callback in the microtask queue. The .then handler does not run immediately.
console.log('End') runs next (still synchronous).
After the synchronous script finishes, the microtask queue runs, logging 'Success'.
Execution order:
Start
End
Success
This matches option B.
JavaScript Knowledge Reference (text-only)
Promise .then() callbacks execute after the current call stack finishes (microtask queue).
Synchronous logs run immediately, before promise callbacks.
==================================================
At Universal Containers, every team has its own way of copying JavaScript objects. The code snippet shows an implementation from one team:
01 function Person() {
02 this.firstName = "John";
03 this.lastName = "Doe";
04 this.name = () => {
05 console.log('Hello ${this.firstName} ${this.lastName}');
06 }
07 }
08
09 const john = new Person();
10 const dan = JSON.parse(JSON.stringify(john)); // (intended deep copy)
11 dan.firstName = 'Dan';
12 dan.name();
(Original line 10 is logically intended to be JSON.parse(JSON.stringify(john)) to perform a JSON clone.)
What is the output of the code execution?
JSON.stringify(john) converts the john object into a JSON string.
When you JSON.parse that string back, you get a plain object:
Only data that can be represented in JSON is preserved (numbers, strings, booleans, arrays, plain objects).
Functions are not preserved and are dropped.
So dan is a plain object with properties firstName and lastName, but no name method.
Therefore, dan.name is undefined, and dan.name() throws:
TypeError: dan.name is not a function
The literal string interpolation inside console.log('Hello ${...}') is also wrong (single quotes), but the code never reaches that line.
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