Question 1

What does async do in front of a function?

Accepted Answer

✅ Marks it as asynchronous

Question 2

The keyword used to mark a function as asynchronous.

Accepted Answer

✅ async

Question 3

The programming model in JavaScript where only one thread executes code at a time.

Accepted Answer

✅ Single-threaded

Question 4

Callbacks were the first method for handling asynchronous operations in JavaScript.

Accepted Answer

✅ True

Question 5

The oldest method for handling asynchronous operations in JavaScript.

Accepted Answer

✅ Callbacks

Question 6

Async/await is syntactic sugar over Promises, making async code look synchronous.

Accepted Answer

✅ True

Question 7

The async keyword marks a function as asynchronous, while await pauses execution until the Promise resolves.

Accepted Answer

✅ True

Question 8

Using sequential await calls instead of Promise.all() results in:

Accepted Answer

✅ Slower execution

Question 9

Using sequential await calls is faster than running Promises in parallel with Promise.all().

Accepted Answer

✅ False

Question 10

The method used to run multiple Promises in parallel and wait for all to complete.

Accepted Answer

✅ Promise.all()

Question 11

The Promise method that returns the first Promise to settle, whether fulfilled or rejected.

Accepted Answer

✅ Promise.race()

Question 12

Promise.race() returns:

Accepted Answer

✅ The first Promise to settle

Question 13

The Promise method that returns the first Promise to fulfill, ignoring rejected Promises.

Accepted Answer

✅ Promise.any()

Question 14

Promises can have which states?

Accepted Answer

✅ Pending, Fulfilled, Rejected

Question 15

The three states a Promise can have.

Accepted Answer

✅ Pending, Fulfilled, Rejected

Question 16

The type of class field that cannot be accessed from outside the class.

Accepted Answer

✅ Private class field

Question 17

Which of the following is true about private class fields?

Accepted Answer

✅ They are declared with # and cannot be accessed outside the class

Question 18

Private class fields in JavaScript are accessible outside of the class using this.#fieldName.

Accepted Answer

✅ False

Question 19

Optional chaining (?.) in JavaScript throws an error if any property in the chain is undefined.

Accepted Answer

✅ False

Question 20

What does optional chaining (?.) do in JavaScript?

Accepted Answer

✅ Returns undefined if any property in the chain is missing

Question 21

The operator that allows you to safely access deeply nested object properties without causing an error.

Accepted Answer

✅ Optional chaining (?.)

Question 22

Nullish coalescing (??) is used to:

Accepted Answer

✅ Replace only null or undefined with a default

Question 23

The operator used to provide a default value only when a variable is null or undefined.

Accepted Answer

✅ Nullish coalescing operator (??)

Question 24

The syntax used to merge arrays or objects in modern JavaScript.

Accepted Answer

✅ Spread operator (...)

Question 25

Which of these operators is used to merge arrays or objects?

Accepted Answer

✅ Spread operator (...)

Question 26

The spread operator (...) can be used to merge arrays and objects.

Accepted Answer

✅ True

Question 27

Destructuring in JavaScript:

Accepted Answer

✅ Extracts values from arrays or objects into variables

Question 28

The syntax used to extract values from arrays or objects into variables.

Accepted Answer

✅ Destructuring

Question 29

Destructuring cannot provide default values for object properties.

Accepted Answer

✅ False

Question 30

The module pattern is used for:

Accepted Answer

✅ Encapsulation and privacy

Question 31

The feature that allows using await outside of async functions in modules.

Accepted Answer

✅ Top-level await

Question 32

Top-level await allows:

Accepted Answer

✅ Awaiting outside async functions in modules

Question 33

Frameworks help manage the DOM, state, routing, and optimize re-renders.

Accepted Answer

✅ True

Question 34

Frameworks are strictly necessary to build any JavaScript application.

Accepted Answer

✅ False

Question 35

Which of the following is a reason to use a JavaScript framework?

Accepted Answer

✅ To manage DOM, state, and routing efficiently

Question 36

What is a primary benefit of component-based architecture?

Accepted Answer

✅ Reusable UI pieces

Question 37

In React, the syntax that allows writing HTML-like code inside JavaScript.

Accepted Answer

✅ JSX

Question 38

JSX in React allows developers to:

Accepted Answer

✅ Write HTML-like syntax in JavaScript

Question 39

JSX allows writing HTML-like syntax directly inside JavaScript.

Accepted Answer

✅ True

Question 40

React’s state can only be used in class components.

Accepted Answer

✅ False

Question 41

React concept used to store data that changes over time within a component.

Accepted Answer

✅ State

Question 42

React Hooks were introduced to:

Accepted Answer

✅ Unify functional and class components

Question 43

Hooks were introduced in React in 2018 to unify functional and class components.

Accepted Answer

✅ True

Question 44

React hook used to manage state in functional components.

Accepted Answer

✅ useState

Question 45

React hook used to handle side effects such as API calls.

Accepted Answer

✅ useEffect

Question 46

Which React hook is used to handle side effects like API calls?

Accepted Answer

✅ useEffect

Question 47

useRef in React is used to manage DOM elements or persist values across renders.

Accepted Answer

✅ True

Question 48

React hook that allows access to context without prop drilling.

Accepted Answer

✅ useContext

Question 49

React strictly requires class components for all applications.

Accepted Answer

✅ False

Question 50

Which framework/library is maintained by Meta/Facebook?

Accepted Answer

✅ React

Question 51

In Vue, reactive data means:

Accepted Answer

✅ Data changes automatically update the UI

Question 52

Vue feature that allows dynamic updates to the UI when data changes.

Accepted Answer

✅ Reactivity system

Question 53

Vue is often described as:

Accepted Answer

✅ A progressive framework

Question 54

The progressive framework that allows incremental adoption, created by a community.

Accepted Answer

✅ Vue.js

Question 55

Vue can be adopted incrementally, from a single component to a full application.

Accepted Answer

✅ True

Question 56

What does Vue Single File Component contain?

Accepted Answer

✅ Template, script, and styles

Question 57

Vue 3 feature that provides more flexibility for organizing component logic, similar to React Hooks.

Accepted Answer

✅ Composition API

Question 58

The Composition API in Vue 3 is:

Accepted Answer

✅ Optional

Question 59

Composables in Vue are similar to which React concept?

Accepted Answer

✅ Custom hooks

Question 60

Which framework uses TypeScript by default and is considered opinionated?

Accepted Answer

✅ Angular

Question 61

Angular is opinionated and uses TypeScript by default.

Accepted Answer

✅ True

Question 62

Angular feature for adding metadata to classes and properties.

Accepted Answer

✅ Decorators

Question 63

Angular’s dependency injection is used to:

Accepted Answer

✅ Manage services efficiently

Question 64

Which feature allows efficient updates without manual DOM manipulation?

Accepted Answer

✅ Virtual DOM

IT0063 - F3&F4

Formative 3 and 4 Advanced Web Design

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