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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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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When connecting to a SQL database, what does the acronym CRUD stand for?

Create, Retrieve, Update, Delete
Connect, Retrieve, Utilize, Deploy
Configure, Render, Update, Distribute
Control, Receive, Use, Define

CRUD stands for Create, Retrieve, Update, Delete. These are the four fundamental operations for managing data in a SQL database. Create adds new records, Retrieve reads data, Update modifies existing records, and Delete removes records.

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The Events module in Node.js extends the ______ class to allow the creation of event emitter instances.

'EventEmitter'
'Emitter'
'Event'
'Listener'

The Events module in Node.js extends the 'EventEmitter' class to allow the creation of event emitter instances. This class provides the functionality for registering event listeners and emitting events.

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A JavaScript file that uses export is considered a ________.

Module
Package
Bundle
Dependency

A JavaScript file that uses the export keyword is considered a "module." Modules are used to encapsulate and export functionality that can be used in other parts of the code.

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What is the primary purpose of the NPM registry in Node.js development?

To install Node.js itself
To manage global packages
To host and distribute Node.js packages and modules
To run JavaScript code

The primary purpose of the NPM (Node Package Manager) registry in Node.js development is to host and distribute Node.js packages and modules. It serves as a centralized repository for sharing and discovering reusable code, making it a crucial component of the Node.js ecosystem. Option 1 is incorrect because NPM is not used to install Node.js itself; you would use a Node.js installer for that. Option 2 is incorrect because NPM primarily manages packages on a project-specific level, not globally. Option 4 is incorrect because the NPM registry is not used to execute JavaScript code directly.

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The Time-To-Live (TTL) value in caching determines how long the data should remain in the cache before being ______.

Refreshed
Expired
Serialized
Evicted

The Time-To-Live (TTL) value in caching determines how long the data should remain in the cache before being expired. When data expires, it is removed from the cache and, if needed, can be fetched again from the source.

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What considerations need to be made for evolving schemas in distributed databases to ensure data consistency?

Distributed databases should never have evolving schemas
Schema changes should be applied simultaneously to all nodes
Schema changes should be applied sequentially with backward compatibility
Schema changes should be applied only to a single node

When evolving schemas in distributed databases, it's important to apply changes sequentially with backward compatibility. This means making changes in a way that allows both old and new versions of the schema to coexist temporarily, ensuring data consistency during the transition. Applying changes simultaneously or only to a single node can lead to data inconsistencies.

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