Quiz about Certification Exam, Salesforce, Salesforce Javascript Developer I Certification

Question 1

A developer is creating a simple webpage with a button. The developer wants a message to be displayed only on the first click of the button, and subsequent clicks should not show the message. The following JavaScript code is used:
const button = document.getElementById('myButton');
function listen(event) {
alert('Hey! I am John Doe');
// What code should be added here?
}
button.addEventListener('click', listen);

Accepted Answer

On line 04, add button.removeEventListener('click', listen);

Accepted Answer

On line 06, use an options object { once: true } with addEventListener().

Answer

Insert a check using if(event.first) to test for the first click.

Answer

On line 04, add event.stopPropagation().

Question 2

Refer to the code below:
01 const exec = (item, delay) =>{
02 new Promise(resolve => setTimeout( () => resolve(item), delay)),
03 async function runParallel() {
04 Const (result1, result2, result3) = await Promise.all{
05 [exec (‘x’, ‘100’) , exec(‘y’, 500), exec(‘z’, ‘100’)]
06 );
07 return `parallel is done: $(result1) $(result2)$(result3)`;
08 }
}
}
Which two statements correctly execute the runParallel () function?
Choose 2 answers

Accepted Answer

runParallel ( ). done(function(data){
return data;
});

Accepted Answer

runParallel () .then(function(data)
return data

Answer

Async runParallel () .then(data);

Answer

runParallel () .then(data);

Question 3

A developer needs to test this function:
01 const sum3 = (arr) => (
02 if (!arr.length) return 0,
03 if (arr.length === 1) return arr[0],
04 if (arr.length === 2) return arr[0] + arr[1],
05 return arr[0] + arr[1] + arr[2],
06 );
Which two assert statements are valid tests for the function?

Choose 2 answers

Accepted Answer

console.assert(sum3(1, ‘2’)) == 12);

Accepted Answer

console.assert(sum3(-3, 2 )) == -1);

Answer

console.assert(sum3(0)) == 0);

Answer

console.assert(sum3(‘hello’, 2, 3, 4)) === NaN);

Question 4

Which statement phrases successfully?

Accepted Answer

JSON.parse(‘ “ foo ” ’);

Answer

JSON.parse ( ‘ foo ’ );

Answer

JSON.parse ( “ foo ” );

Answer

JSON.parse( “ ‘ foo ’ ” );

Question 5

Refer to the code below:
01 let car1 = new promise((_, reject) =>
02 setTimeout(reject, 2000, “Car 1 crashed in”));
03 let car2 = new Promise(resolve => setTimeout(resolve, 1500, “Car 2
completed”));
04 let car3 = new Promise(resolve => setTimeout (resolve, 3000, “Car 3
Completed”));
05 Promise.race([car1, car2, car3])
06 .then(value => (
07 let result = $(value) the race. `;
08 ))
09 .catch( arr => (
10 console.log(“Race is cancelled.”, err);
11 ));
What is the value of result when Promise.race executes?

Accepted Answer

Car 2 completed the race.

Answer

Car 3 completed the race.

Answer

Car 1 crashed in the race.

Answer

Race is cancelled.

Question 6

Refer to the code below:
for(let number =2 ; number <= 5 ; number += 1 ) {
// insert code statement here
}
The developer needs to insert a code statement in the location shown. The code
statement has these requirements:
1. Does require an import
2. Logs an error when the boolean statement evaluates to false
3. Works in both the browser and Node.js
Which meet the requirements?

Accepted Answer

console.error(number % 2 === 0);

Answer

assert (number % 2 === 0);

Answer

console.debug(number % 2 === 0);

Answer

console.assert(number % 2 === 0);

Question 7

A developer is working on an ecommerce website where the delivery date is dynamically
calculated 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’s
date + 9 days.
Which code meets this new requirement?

Accepted Answer

deliveryDate.setDate(( new Date ( )).getDate () +9);

Answer

deliveryDate.setDate( Date.current () + 9);

Answer

deliveryDate.date = new Date(+9) ;

Answer

deliveryDate.date = Date.current () + 9;

Question 8

Which three statements are true about promises ?
Choose 3 answers

Accepted Answer

A Promise has a .then() method.

Accepted Answer

A fulfilled or rejected promise will not change states .

Accepted Answer

A pending promise can become fulfilled, settled, or rejected.

Answer

The executor of a new Promise runs automatically.

Answer

A settled promise can become resolved.

Question 9

Given the code below:
01 function GameConsole (name) {
02 this.name = name;
03 }
04
05 GameConsole.prototype.load = function(gamename) {
06 console.log( ` $(this.name) is loading a game : $(gamename) …`);
07 )
08 function Console 16 Bit (name) {
09 GameConsole.call(this, name) ;
10 }
11 Console16bit.prototype = Object.create ( GameConsole.prototype) ;
12 //insert code here
13 console.log( ` $(this.name) is loading a cartridge game : $(gamename) …`);
14 }
15 const console16bit = new Console16bit(‘ SNEGeneziz ’);
16 console16bit.load(‘ Super Nonic 3x Force ’);
What should a developer insert at line 15 to output the following message using the
method ?
> SNEGeneziz is loading a cartridge game: Super Monic 3x Force . . .

Accepted Answer

Console16bit.prototype.load = function(gamename) {

Answer

Console16bit.prototype.load(gamename) = function() {

Answer

Console16bit = Object.create(GameConsole.prototype).load = function
(gamename) {

Answer

Console16bit.prototype.load(gamename) {

Question 10

A developer has the following array of student test grades:
Let arr = [ 7, 8, 5, 8, 9 ];
The Teacher wants to double each score and then see an array of the students
who scored more than 15 points.
How should the developer implement the request?

Accepted Answer

Let arr1 = arr.map((num) => num*2). Filter (( val) => val > 15);

Answer

Let arr1 = arr.filter(( val) => ( return val > 15 )) .map (( num) => ( return num *2 ))

Answer

Let arr1 = arr.mapBy (( num) => ( return num *2 )) .filterBy (( val ) => return val > 15 )) ;

Answer

Let arr1 = arr.map((num) => ( num *2)).filterBy((val) => ( val >15 ));

Quiz Salesforce Javascript Developer I Certification

Teste gratuito - Simulador Salesforce Javascript Developer I Certification

Salesforce Javascript Developer I Certification Teste de prática desbloqueia todas as perguntas do simulador online

O que esperar de nossos testes práticos Salesforce Javascript Developer I Certification e como se preparar para qualquer exame?