Salesforce JAVASCRIPT-DEVELOPER-I Online Practice Questions and Exam Preparation

Salesforce JAVASCRIPT-DEVELOPER-I Online Questions & Answers

• Question 91:

  Refer to the following code block:

  class Animal{

  constructor(name){

  this.name = name;

  }

  makeSound(){

  console.log(`${this.name} is making a sound.`)

  }

  }

  class Dog extends Animal{

  constructor(name){

  super(name)

  this.name = name;

  }

  makeSound(){

  console.log(`${this.name} is barking.`)

  }

  }

  let myDog = new Dog('Puppy');

  myDog.makeSound();

  What is the console output?

  A. Puppy is barking
  B. PlaceHolder
  C. PlaceHolder
  D. PlaceHolder
  A. Puppy is barking

• Question 92:

  A developer needs to debug a Node.js web server because a runtime error keeps occurring at one of the endpoints.

  The developer wants to test the endpoint on a local machine and make the request against a local server to look at the behavior. In thesource code, the server, js file will start the server. the developer wants to debug the Node.js server only

  using the terminal.

  Which command can the developer use to open the CLI debugger in their current terminal window?

  A. node -i server.js
  B. node inspect server,js
  C. node server,js inspect
  D. node start inspect server,js
  B. node inspect server,js

• Question 93:

  Which statement accurately describes an aspect of promises?

  A. Arguments for the callback function passed to .then() are optional.
  B. In a.then()function, returning results is not necessary since callbacks will catch the result of a previous promise.
  C. .then() cannot be added after a catch.
  D. .then() manipulates and returns the original promise.
  A. Arguments for the callback function passed to .then() are optional.

• Question 94:

  A developer creates a simple webpage with an input field. When a user enters text in the input field and clicks the button, the actual value of the field must bedisplayed in the console.

  Here is the HTML file content:

  Display The developer wrote the javascript code below:

  Const button = document.querySelector(`button');

  button.addEvenListener(`click', () => (

  Const input = document.querySelector(`input');

  console.log(input.getAttribute(`value'));

  When the user clicks the button, the output is always "Hello". What needs to be done to make this code work as expected?

  A. Replace line 04 with console.log(input .value);
  B. Replace line 03 with const input = document.getElementByName(`input');
  C. Replace line 02 with button.addCallback("click", function() {
  D. Replace line 02 with button.addEventListener("onclick", function() {
  A. Replace line 04 with console.log(input .value);

• Question 95:

  Refer to the following object:

  const cat ={

  firstName: `Fancy',

  lastName: ` Whiskers',

  Get fullName() {

  return this.firstName + ` ` + this.lastName;

  }

  };

  How can a developer access the fullName property for cat?

  A. cat.fullName
  B. cat.fullName()
  C. cat.get.fullName
  D. cat.function.fullName()
  A. cat.fullName

• Question 96:

  Which javascript methods can be used to serialize an object into a string and deserialize a JSON string into an object, respectively?

  A. JSON.stringify and JSON.parse
  B. JSON.serialize and JSON.deserialize
  C. JSON.encode and JSON.decode
  D. JSON.parse and JSON.deserialize
  A. JSON.stringify and JSON.parse

• Question 97:

  Refer tothe following code that imports a module named utils:

  import (foo, bar) from `/path/Utils.js';

  foo() ;

  bar() ;

  Which two implementations of Utils.js export foo and bar such that the code above runs without error?

  Choose 2 answers

  A. // FooUtils.js and BarUtils.js exist Import (foo) from `/path/FooUtils.js'; Import (boo) from ` /path/NarUtils.js';
  B. const foo = () => { return `foo' ; } const bar = () => { return `bar' ; } export { bar, foo }
  C. Export default class { foo() { return `foo' ; } bar() { return`bar' ; } }
  D. const foo = () => { return `foo';} const bar = () => {return `bar'; } Export default foo, bar;
  B. const foo = () => { return `foo' ; } const bar = () => { return `bar' ; } export { bar, foo }
  C. Export default class { foo() { return `foo' ; } bar() { return`bar' ; } }

• Question 98:

  Given the following code:

  

  is the output of line 02?

  A. ''x''
  B. ''null'''
  C. ''object''
  D. ''undefined''
  C. ''object''

• Question 99:

  Universal Containers (UC)notices that its application that allows users to search for accounts makes a network request each time a key is pressed. This results in too many requests for the server to handle.

  Address this problem, UC decides to implement a debounce function on string change handler.

  What are three key steps to implement this debounce function?

  Choose 3 answers:

  A. If there is an existing setTimeout and the search string change, allow the existing setTimeout to finish, and do not enqueue a new setTimeout.
  B. When the search string changes, enqueue the request within a setTimeout.
  C. Ensure that the network request has the property debounce set to true.
  D. If there is an existing setTimeout and the search string changes, cancel the existing setTimeout using thepersisted timerId and replace it with a new setTimeout.
  E. Store the timeId of the setTimeout last enqueued by the search string change handle.
  A. If there is an existing setTimeout and the search string change, allow the existing setTimeout to finish, and do not enqueue a new setTimeout.
  B. When the search string changes, enqueue the request within a setTimeout.
  C. Ensure that the network request has the property debounce set to true.

• Question 100:

  A developer wants to set up a secure web serverwith Node.js. The developer creates a directory locally called app-server, and the first file is app-server/index.js Without using any third-party libraries, what should the developer add to index.js to create the secure web server?

  A. const https =require(`https');
  B. const server =require(`secure-server');
  C. const tls = require(`tls');
  D. const http =require(`http');
  A. const https =require(`https');