Salesforce Salesforce Certifications JAVASCRIPT-DEVELOPER-I Questions & Answers

• Question 41:

  Developer creates a new web server that uses Node.js. It imports a server library that uses events and callbacks for handling server functionality.

  The server library is imported with require and is made available to the code by a variable named server. The developer wants to log any issues that the server has while booting up.

  Given the code and the information the developer has, which code logs an error at boost with an event?

  A. Server.catch ((server) => { console.log(`ERROR', error); });

  B. Server.error ((server) => { console.log(`ERROR', error); });

  C. Server.on (`error', (error) => { console.log(`ERROR', error); });

  D. Try{ server.start(); } catch(error) { console.log(`ERROR', error); }

  Correct Answer: C

• Question 42:

  Given two expressions var1 and var2. What are two valid ways to return the logical AND of the two expressions and ensure it is data type Boolean?

  Choose 2 answers:

  A. Boolean(var1 andand var2)

  B. var1 andand var2

  C. var1.toBoolean() andand var2toBoolean()

  D. Boolean(var1) andand Boolean(var2)

  Correct Answer: AD

• Question 43:

  Which three actions can be using the JavaScript browser console?

  Choose 3 answers:

  A. View and change DOM the page.

  B. Display a report showing the performance of a page.

  C. Run code that is not related to page.

  D. view , change, and debug the JavaScript code of the page.

  E. View and change security cookies.

  Correct Answer: ACD

• Question 44:

  Which statement accurately describes the behaviour of the async/ await keyworks ?

  A. The associated class contains some asynchronous functions.

  B. The associated function will always return apromise

  C. The associated function can only be called via asynchronous methods

  D. The associated sometimes returns a promise.

  Correct Answer: B

• Question 45:

  A developer is leading the creation of a new browser application that will serve a single page application. The team wants to use a new web framework Minimalsit.js.The Lead developer wants to advocate for a more seasoned web framework that already has a community around it.

  Which two frameworks should the lead developer advocate for?

  Choose 2 answers

  A. Vue

  B. Angular

  C. Koa

  D. Express

  Correct Answer: BD

• Question 46:

  A developer copied a JavaScript object:

  

  How does the developer access dan's forstName,lastName? Choose 2 answers

  A. dan,name

  B. dan,firstname ( ) + dan, lastName ( )

  C. dan, firstName = dan.lastName

  D. dan,name ( )

  Correct Answer: CD

• Question 47:

  Consider type coercion, what does the following expression evaluate to? True + 3 + `100' + null

  A. 104

  B. 4100

  C. `3100null'

  D. `4100null'

  Correct Answer: D

• Question 48:

  Refer to the code below:

  const car = {

  price:100,

  getPrice:function(){

  return this.price;

  }

  };

  const customCar = Object.create(car);

  customCar.price = 70;

  delete customCar.price;const result = customCar.getPrice();

  Whatis the value of result after the code executes?

  A. 100

  B. undefined

  C. null

  D. 70

  Correct Answer: A

• Question 49:

  A developer is trying to handle an error within a function.

  Which code segment shows the correct approach to handle an error without propagating it elsewhere?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: D

• Question 50:

  Refer to the following code:

  CLick me