Salesforce Javascript-Developer-I Exam Dumps

Salesforce Javascript-Developer-I Sample Question Answers

Question # 1

A developer wants to define a function log to be used a few times on a single-fileJavaScript script.01 // Line 1 replacement02 console.log('"LOG:', logInput);03 }Which two options can correctly replace line 01 and declare the function for use?Choose 2 answers

A. function leg(logInput) {
B. const log(loginInput) {
C. const log = (logInput) => {
D. function log = (logInput) {

Show Answer

Question # 2

A developer wants to create an object from a function in the browser using the codebelow:Function Monster() { this.name =‘hello’ };Const z = Monster();What happens due to lack of the new keyword on line 02?

A. The z variable is assigned the correct object.
B. The z variable is assigned the correct object but this.name remains undefined.
C. Window.name is assigned to ‘hello’ and the variable z remains undefined.
D. Window.m is assigned the correct object.

Show Answer

Question # 3

A developer uses a parsed JSON string to work with userinformation as in the block below:01 const userInformation ={02 “ id ” : “user-01”,03 “email” : “user01@universalcontainers.demo”,04 “age” : 25Which two options access the email attribute in the object?Choose 2 answers

A. userInformation(“email”)
B. userInformation.get(“email”)
C. userInformation.email
D. userInformation(email)

Show Answer

Question # 4

Considering type coercion, what does the following expression evaluate to?True + ‘13’ + NaN

A. ‘ 113Nan ’
B. 14
C. ‘ true13 ’
D. ‘ true13NaN ’

Show Answer

Question # 5

A developer creates a class that represents a blog post based on the requirement that aPost should have a body author and view count.The Code shown Below:ClassPost {// Insert code hereThis.body =bodyThis.author = author;this.viewCount = viewCount;}}Which statement should be inserted in the placeholder on line 02 to allow for a variable tobe setto a new instanceof a Post with the three attributes correctly populated?

A. super (body, author, viewCount) {
B. Function Post (body, author, viewCount) {
C. constructor (body, author, viewCount) {
D. constructor() {

Show Answer

Question # 6

Refer to the code below:Let foodMenu1 =[‘pizza’, ‘burger’, ‘French fries’];Let finalMenu = foodMenu1;finalMenu.push(‘Garlic bread’);What is the value of foodMenu1 after the code executes?

A. [ ‘pizza’,’Burger’, ‘French fires’, ‘Garlic bread’]
B. [ ‘pizza’,’Burger’, ‘French fires’]
C. [ ‘Garlic bread’ , ‘pizza’,’Burger’, ‘French fires’ ]
D. [ ‘Garlic bread’]

Show Answer

Question # 7

Which three statements are true about promises ?Choose 3 answers

A. The executor of a new Promise runs automatically.
B. A Promise has a .then() method.
C. A fulfilled or rejected promise will not change states .
D. A settled promise can become resolved.
E. A pending promise canbecome fulfilled, settled, or rejected.

Show Answer

Question # 8

A developer creates an object where its properties should be immutable and preventproperties from being added or modified.Which method shouldbe used to execute this business requirement ?

A. Object.const()
B. Object.eval()
C. Object.lock()
D. Object.freeze()

Show Answer

Question # 9

Refer to the code below:const event = new CustomEvent(//Missing Code );obj.dispatchEvent(event);A developer needs to dispatch a custom event called update to send information aboutrecordId.Which two options could a developer insert at the placeholder in line 02 to achieve this?Choose 2 answers

A. ‘Update’ , (recordId : ‘123abc’(
B. ‘Update’ , ‘123abc’
C. { type : ‘update’, recordId : ‘123abc’ }
D. ‘Update’ , { Details : { recordId : ‘123abc’ } }

Show Answer

Question # 10

A developer creates a simple webpage with an input field. When a user enters text in theinput field and clicks the button, the actual value of the field must be displayed in theconsole.Here is the HTML file content:<input type =” text” value=”Hello” name =”input”><button type =”button” >Display </button> 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 withbutton.addEventListener(“onclick”, function() {

Show Answer

Question # 11

Refer to the following code:<html lang=”en”><body><div onclick = “console.log(‘Outer message’) ;”><button id =”myButton”>CLick me<button></div></body><script>function displayMessage(ev) {ev.stopPropagation();console.log(‘Inner message.’);}const elem =document.getElementById(‘myButton’);elem.addEventListener(‘click’ , displayMessage);</script></html>What will the console show when the button is clicked?

A. Outer message
B. Outer message Inner message
C. Inner message Outer message
D. Inner message

Show Answer

Question # 12

Refer to the code below:Async funct on functionUnderTest(isOK) {If (isOK) return ‘OK’ ;Throw new Error(‘not OK’);)Which assertion accuretely tests the above code?

A. Console.assert (await functionUnderTest(true), ‘ OK ’)
B. Console.assert (await functionUnderTest(true), ‘ not OK ’)
C. Console.assert (awaitfunctionUnderTest(true), ‘ not OK ’)
D. Console.assert (await functionUnderTest(true), ‘OK’)

Show Answer

Question # 13

A developer writers the code below to calculate the factorial of a given number.Function factorial(number) {Return number + factorial(number -1);}factorial(3);What isthe result of executing line 04?

A. 0
B. 6
C. -Infinity
D. RuntimeError

Show Answer

Question # 14

Refer to the code below:01 const server = require(‘server’);02 /* Insert code here */A developer imports a library that creates a web server.The imported library uses eventsandcallbacks to start the serversWhich code should be inserted at the line 03 to set up an event and start the web server ?

A. Server.start ();
B. server.on(‘ connect ’ , ( port) => { console.log(‘Listening on ’ , port);})
C. server()
D. serve(( port) => (
E. console.log( ‘Listening on ’, port) ;

Show Answer

Question # 15

A developer wants to iterate through an array of objects and count the objects and countthe objects whose property value, name, starts with the letter N.Const arrObj = [{“name” : “Zach”} , {“name” : “Kate”},{“name” : “Alise”},{“name” :“Bob”},{“name” :“Natham”},{“name” : “nathaniel”}Refer to the code snippet below:01 arrObj.reduce(( acc, curr) => {02 //missing line 0202 //missing line 0304 ).0);Which missing lines 02 and 03 return the correct count?

A. Const sum = curr.startsWith(‘N’) ? 1: 0;Return acc +sum
B. Const sum = curr.name.startsWith(‘N’) ? 1: 0;Return acc +sum
C. Const sum = curr.startsWIth(‘N’) ? 1: 0;Return curr+ sum
D. Constsum = curr.name.startsWIth(‘N’) ? 1: 0;Return curr+ sum

Show Answer

Question # 16

Giventhe code below:const copy = JSON.stringify([ new String(‘ false ’), new Bollean( false ), undefined ]);What is the value of copy?

A. -- [ \”false\” , { } ]--
B. -- [ false, { } ]--
C. -- [ \”false\” , false, undefined ]--
D. -- [ \”false\” ,false, null ]--

Show Answer

Question # 17

A developer is working on an ecommerce website where the delivery date is dynamicallycalculated based on the current day. The code line below is responsible for this calculation.Const deliveryDate = new Date ();Due to changes in the business requirements, the delivery date must now be today’sdate + 9 days.Which code meets thisnew requirement?

A. deliveryDate.setDate(( new Date ( )).getDate () +9);
B. deliveryDate.setDate( Date.current () + 9);
C. deliveryDate.date = new Date(+9) ;
D. deliveryDate.date = Date.current () + 9;

Show Answer

Question # 18

Which function should a developer use to repeatedly execute code at a fixed interval ?

A. setIntervel
B. setTimeout
C. setPeriod
D. setInteria

Show Answer

Question # 19

developer is trying to convince management that their team will benefit from usingNode.js for a backend server that they are going to create. The server will be a web serverthathandles API requests from a website that the team has already built using HTML, CSS,andJavaScript.Which three benefits of Node.js can the developer use to persuade their manager?Choose 3 answers:

A. I nstalls with its own package manager toinstall and manage third-party libraries.
B. Ensures stability with one major release every few years.
C. Performs a static analysis on code before execution to look for runtime errors.
D. Executes server-side JavaScript code to avoid learning a new language.
E. User non blocking functionality for performant request handling .

Show Answer

Question # 20

A developer receives a comment from the Tech Lead that the code given below haserror:const monthName = ‘July’;const year = 2019;if(year === 2019) {monthName = ‘June’;}Which line edit should be made to make this code run?

A. 01 let monthName =’July’;
B. 02 let year =2019;
C. 02 const year = 2020;
D. 03 if (year == 2019) {

Show Answer

Question # 21

A developer wrote the following code: 01 let X = object.value; 02 03 try { 04 handleObjectValue(X); 05 } catch (error) { 06 handleError(error); 07 }The developer has a getNextValue function to execute after handleObjectValue(), but does not want to execute getNextValue() if an error occurs.How can the developer change the code to ensure thisbehavior?

A. 03 try{ 04 handleObjectValue(x); 05 } catch(error){ 06 handleError(error); 07 } then { 08 getNextValue(); 09 }
B. 03 try{ 04 handleObjectValue(x); 05 } catch(error){ 06 handleError(error); 07 } finally { 08 getNextValue(); 10 }
C. 03 try{ 04handleObjectValue(x); 05 } catch(error){ 06 handleError(error); 07 } 08 getNextValue();
D. 03 try { 04 handleObjectValue(x) 05 ……………………

Show Answer

Question # 22

Which three browser specific APIs are available for developers to persist data betweenpage loads ?Choose 3 answers

A. IIFEs
B. indexedDB
C. Global variables
D. Cookies
E. localStorage.

Show Answer