Set 1-4

A visually engaging illustration of a JavaScript code editor with dynamic elements, quiz scoreboards, and colorful UI design elements representing coding, learning, and development.

JavaScript Proficiency Quiz

Test your JavaScript knowledge with our engaging quiz designed for developers of all levels. This quiz includes a variety of questions that cover fundamental concepts, advanced topics, and practical coding scenarios.

10 challenging questions
Multiple choice and checkbox formats
Assess your coding skills and knowledge

10 Questions2 MinutesCreated by CodingCat321

Given the code below:

01 setCurrentUrl();

02 console.log('The current URL is: ' +url);

03

04 function setCurrentUrl() {

05 url = window.location.href;

06 }

What happens when the code executes?

The url variable has local scope and line 02 executes correctly

The url variable has local scope and line 02 throws an error

The url variable has global scope and line 02 executes correctly

The url variable has global scope and line 02 throws and error

Refer to the code below:

01 document.body.addEventListener('click', (event) => {

02 if(/* ANSWER HERE */){

03 console.log('myElement clicked');

04 }

05 });

Which replacement for the conditional statement on line 02 allows a developer to correctly determine that a specific element, myElement, on the page had been clicked?

E.nodeTarget == myElement

Button.addEventListener('click', 'myElement')

Event.target.id == 'myElement'

MyElement.clicked

Refer to the code below:

01 new Promise((resolve, reject) => {

02 const fraction = Math.random();

03 if(fraction > 0.5) reject('fraction > 0.5, ' + fraction);

04 resolve(fraction);

05 })

06 .then(() => console.log('resolved'))

07 .catch((error) => console.error(error))

08 .finally(() => console.log('when am I called?'));

When does Promise.finally on line 08 get called?

When resolved

When resolved and settled

When resolved or rejected

When rejected

A tesst has a dependency on database.query. During the test the dependency is replaced with an object called database with the method, query, that returns an array. The developer needs to verify how many times the method was called and the arguments used each time.

Which two test approaches describe the requirement?

Choose 2 answers

Integration

Mocking

White box

Black box

A developer created a generic function to log custom messages shown in the code below.

function myLog(message){

console./*Answer goes here*/ ('Custom log: ' +message);

}

Which three options can the developer use to log custom messages in the console?

Choose 3 answers

Cloud Kicks has a class to represent shoes for sale in an online store, as shown below:

01 class Shoe {

02 constructor(name, price) {

03 this.name = name;

04 this.price = price;

05 }

06

07 formattedPrice() {

08 return '$' + String(this.price);

09 }

10 }

A new business requirement comes in that requests a Sneaker class, that should have all of the properties and methods of the Shoe class, but will also have properties that are specific to sneakers.

Which line of code properly declares the Sneaker class such that it inherits from Shoe?

Class Shoe extends Sneaker {

Class Sneaker implements Shoe {

Class Sneaker extends Shoe {

Class Sneaker {

Refer to the code below:

let country = {

get capital() {

let city = Number("London");

return {

cityString: city.toString(),

}

Which value van a developer expect when referencing country.capital.cityString?

An error

"NaN"

Undefined

'London'

Set 1-4

JavaScript Proficiency Quiz

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