JavaScript-Developer-I Salesforce Certified JavaScript Developer I (SU24) Questions and Answers

Refer to the code below:

console.log(‘’start);

Promise.resolve(‘Success’) .then(function(value){

console.log(‘Success’);

});

console.log(‘End’);

What is the output after the code executes successfully?

Which code change should be done for the console to log the following when 'Click me!' is clicked'

> Row log

> Table log

Given the code below:

const copy = JSON.stringify([ new String(‘ false ’), new Bollean( false ), undefined ]);

What is the value of copy?

Universal Containers (UC) just launched a new landing page, but users complain that the website is slow. A developer found some functions any that might cause this problem. To verify this, the developer decides to execute everything and log the time each of these three suspicious functions consumes.

Which function can the developer use to obtain the time spent by every one of the three functions?

Refer to the code below:

Async funct on functionUnderTest(isOK) {

If (isOK) return ‘OK’ ;

Throw new Error(‘not OK’);

)

Which assertion accurately tests the above code?

Refer to code below:

Let productSKU = ‘8675309’ ;

A developer has a requirement to generate SKU numbers that are always 19 characters lon,

starting with ‘sku’, and padded with zeros.

Which statement assigns the values sku0000000008675309 ?

A developer wrote the following code to test a sum3 function that takes in an array of numbers and returns the sum of the first three numbers in the array, and the test passes.

A different developer made changes to the behavior of sum3 to instead sum only the first two numbers present in the array.

Which two results occur when running this test on the updated sum3 function?

Choose 2 answers

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 . . .

What is the result of the code block?

Refer to the code below:

const addBy = ?

const addByEight =addBy(8);

const sum = addBYEight(50);

Which two functions can replace line 01 and return 58 to sum?

Choose 2 answers

A test has a dependency on database. query. During the test, the dependency is replaced with an object called database with the method,

Calculator query, that returns an array. The developer does not need to verify how many times the method has been called.

Which two test approaches describe the requirement?

Choose 2 answers

Refer to the code below:

Let car1 = new Promise((_ , reject) =>

setTimeout(reject, 2000, “car 1 crashed in” =>

Let car2 =new Promise(resolve => setTimeout(resolve, 1500, “car 2 completed”)

Let car3 =new Promise(resolve => setTimeout(resolve, 3000, “car 3 completed”)

Promise.race(( car1, car2, car3))

.then (value => (

Let result = ‘$(value) the race.’;)}

.catch(arr => {

console.log(“Race is cancelled.”, err);

});

What is the value of result when Promise.race executes?

Refer to following code:

class Vehicle {

constructor(plate) {

This.plate =plate;

}

}

Class Truck extends Vehicle {

constructor(plate, weight) {

//Missing code

This.weight = weight;

}

displayWeight() {

console.log(‘The truck ${this.plate} has a weight of ${this.weight} lb.’);}}

Let myTruck = new Truck(‘123AB’, 5000);

myTruck.displayWeight();

Which statement should be added to line 09 for the code to display ‘The truck 123AB has a

weight of 5000lb.’?

A developer wants to use a module called DataPrettyPrint. This module exports one default function called printDate ().

How can a developer import and use the printDate() function?

A)

B)

C)

D)

Refer to the following code block:

What is the console output?

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)

B)

C)

D)

A developer wants to use a try...catch statement to catch any error that countSheep () may throw and pass it to a handleError () function.

What is the correct implementation of the try...catch?

A)

B)

C)

D)

Which two code snippets show working examples of a recursive function?

Choose 2 answers

Refer to code below:

Let first = ‘who’;

Let second = ‘what’;

Try{

Try{

Throw new error(‘Sad trombone’);

}catch (err){

First =’Why’;

}finally {

Second =’when’;

} catch (err) {

Second =’Where’;

}

What are the values for first and second once the code executes ?

The developer wants to test this code:

Const toNumber =(strOrNum) => strOrNum;

Which two tests are most accurate for this code?

Choose 2 answers

A developer creates an object where its properties should be immutable and prevent

properties from being added or modified.

Which method should be used to execute this business requirement ?

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

At Universal Containers, every team has its own way of copying JavaScript objects. The code snippet shows an Implementation from one team:

What is the output of the code execution?

Refer to the code below:

What is the value of result when the code executes?

Refer to the following code:

What is the output of line 11?

Given the code below:

const delay = async delay =>{

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

console.log(1);

setTimeout(resolve,deleay);

});

};

const callDelay = async ()=>{

console.log(2);

const yup = await delay(1000);

console.log(3);

}

console.log(4);

callDelay();

console.log(5);

What is logged to the console?

Refer to the code below:

function changeValue(param) {

Param =5;

}

Let a =10;

Let b =5;

changeValue(b);

Const result = a+ “ - ”+ b;

What is the value of result when code executes?

Refer to the following code:

What will the console show when the button is clicked?

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?

Refer to the code below:

Const myFunction = arr => {

Return arr.reduce((result, current) =>{

Return result = current;

}, 10};

}

What is the output of this function when called with an empty array ?