Which JavaScript expression uses the rest operator?

function myFunction(a, b, ...rest)
const [x, y, ...rest] = arr;
const {x, y, ...rest} = obj;
const rest = [a, b, ...c];

The rest operator (...) is used in function parameters to collect all remaining arguments into an array. In the example function myFunction(a, b, ...rest), the ...rest collects any additional arguments passed to the function into an array named rest.

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How can you make the properties of an object immutable in JavaScript?

Using Object.freeze()
Using Object.preventExtensions()
Using Object.seal()
Using Object.makeImmutable()

To make the properties of an object immutable in JavaScript, you can use the Object.freeze() method. This method prevents any changes to the object's properties, making them read-only. The other options, Object.preventExtensions() and Object.seal(), allow some level of modification but not full immutability, and Object.makeImmutable() is not a valid method in JavaScript.

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When creating a multidimensional array in JavaScript, each element of the main array is ______.

an object
a reference
a function
a prototype

When creating a multidimensional array in JavaScript, each element of the main array is a reference to another array or value. This allows for the creation of nested arrays. Changes made to the referenced arrays will affect the main array.

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How can you execute a block of code multiple times, as long as a specified condition is true, in JavaScript?

for loop
while loop
if statement
switch statement

In JavaScript, you can use a while loop to execute a block of code repeatedly as long as a specified condition is true. The for loop is used for iterating over a sequence, and if and switch statements are conditional constructs, not loops.

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You are developing a Node.js application where you need to perform a specific action immediately after the current operation completes. How would you use the process object to schedule this action?

process.scheduleImmediate(() => { /* Action code */ });
process.nextTick(() => { /* Action code */ });
process.setImmediate(() => { /* Action code */ });
process.waitForNext(() => { /* Action code */ });

To schedule a specific action immediately after the current operation completes, you should use process.setImmediate(() => { /* Action code */ });. This ensures that the action is placed in the event queue and executed as soon as possible after the current operation. The other options do not serve this purpose correctly.

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What type of files are generally served as static files in Express.js?

HTML files
Dynamic server scripts
Configuration files
Images, CSS, JavaScript

In Express.js, static files typically include images, CSS files, and JavaScript files. These files do not change dynamically and can be served directly to clients. HTML files are often dynamically generated, and configuration files are not typically served as static files.

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Which of the following is a commonly used configuration file for ESLint?

.eslintrc.json
.eslint-config
.eslint-settings
.lintfile

The commonly used configuration file for ESLint is .eslintrc.json. This file allows you to specify ESLint rules, plugins, and other configuration options for your project.

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Which of the following HTTP methods is typically used for reading data in CRUD operations?

GET
POST
PUT
DELETE

The GET HTTP method is used for reading data in CRUD (Create, Read, Update, Delete) operations. It retrieves data from the server without making any modifications.

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In EJS, to output data to the template, you use the <%= %> syntax, whereas to execute JavaScript code, you use the ______ syntax.

<%# %>
<%$ %>
<%* %>
<% %>

In EJS (Embedded JavaScript), you use <%= %> to output data to the template and <% %> to execute JavaScript code within the template. The other options are not valid EJS syntax.

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To perform setup activities before every test case in a suite in Mocha, you can use the ______ hook.

before
beforeEach
setup
suiteSetup

In Mocha, the beforeEach hook is used to perform setup activities before every test case within a suite. It runs before each test case. The other options (before, setup, and suiteSetup) represent different hook names or are not used for this specific purpose in Mocha.

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