Salesforce JS-Dev-101 Exam Dumps

We need to track the value of counter and the timing of each call to logCounter.

Initial state:

Line 01: counter = 0;

Line 02--04: logCounter logs the current value of counter.

Execution order and timing:

Line 05: logCounter();

Called immediately at time t = 0 ms.

counter is 0.

First log: 0.

Line 06: setTimeout(logCounter, 2100);

Schedules logCounter to run once after 2100 ms.

No log yet at this line.

Line 07--10: setInterval(() => { counter++; logCounter(); }, 1000);

Schedules a repeating callback every 1000 ms (1 second).

First interval callback runs at t 1000 ms.

Now follow the timeline:

t = 0 ms:

logCounter(); from line 05

Logs: 0

t = 1000 ms (first interval execution):

counter++; counter goes from 0 to 1.

logCounter(); logs 1.

t = 2000 ms (second interval execution):

counter++; counter goes from 1 to 2.

logCounter(); logs 2.

t = 2100 ms (timeout from line 06):

logCounter(); runs again.

counter is still 2 (next setInterval will be at t = 3000 ms).

Logs 2.

So the first four logs are:

0

1

2

2

Concatenated as in the options: 0122.

Therefore, the correct choice is:

Answe r: A

Study Guide / Concept Reference (no links):

setTimeout and setInterval timing behavior

Order of execution in the event loop

Closures capturing variables (here, logCounter using counter)

Understanding asynchronous scheduling in JavaScript

Facts about JavaScript Promises:

runParallel() is declared async, which means it always returns a Promise.

Promises are consumed using .then(), .catch(), and .finally().

There is no .done() method in native JavaScript Promises.

The async keyword cannot be placed before a function call (option A is invalid syntax).

Analysis of each option:

A . async runParallel().then(data);

Invalid syntax. async cannot prefix an expression.

B . Valid. Calls the function and attaches a .then() handler.

C . Invalid. .done() is not part of JavaScript Promise API.

D . Valid. Calls runParallel() and chains .then().

Therefore the correct answers are B and D.

JavaScript Knowledge Reference (text-only)

async functions return Promises.

Promises use .then() to retrieve resolved values.

.done() is not part of the standard Promise interface.

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document.cookie retrieves the cookie string.

Setting document.cookie = 'key=John Smith' adds or updates only that one cookie.

Important details:

Writing to document.cookie does not overwrite all cookies.

The browser does not require URL encoding, though it is recommended. Non-encoded spaces are allowed and automatically handled.

document.cookies does not exist; the correct property is document.cookie.

Therefore, the correct behavior:

Cookies are read.

A new cookie key=John Smith is set.

Existing cookies remain.

JavaScript Knowledge Reference (text-only)

Writing document.cookie appends or updates cookies, not replaces them.

document.cookie is both getter and setter for cookie strings.

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Semantic versioning: MAJOR.MINOR.PATCH

MAJOR: incompatible API changes.

MINOR: add functionality in a backward compatible manner.

PATCH: backward compatible bug fixes.

Here:

Bug fixes only, no breaking changes increment PATCH.

From 2.1.1 to 2.1.2.

So the correct new version is 2.1.2.

The browser console (Developer Tools Console) allows:

Running code unrelated to the page

Developers can type arbitrary JavaScript not tied to the page's logic.

This is allowed A is correct.

Viewing and modifying JavaScript code execution

Using the Sources tab and console, developers can:

Inspect variables

Modify code at runtime

Set breakpoints

Therefore D is correct.

Viewing and manipulating the DOM

From the console, developers can:

Query DOM nodes using selectors

Modify element properties and attributes

Insert or remove elements

Therefore E is correct.

Why the other options are incorrect:

B (security cookies)

Many cookies have flags such as HttpOnly and Secure.

Cookies with the HttpOnly flag cannot be viewed or modified via JavaScript or console.

Therefore this is not guaranteed incorrect.

C (performance report)

The console itself does not provide a performance report.

The Performance or Lighthouse tabs provide this, not the console.

Therefore incorrect.

JavaScript Knowledge Reference (text-only)

Developer console can execute arbitrary JavaScript.

Console allows DOM inspection and manipulation.

Security cookies (HttpOnly) cannot be accessed via JavaScript.

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