Salesforce Javascript-Developer-I Question Answers

Question # 31

Refer to the code below: let o = { get js() { let city1 = String("st. Louis"); let city2 = String(" New York"); return { firstCity: city1.toLowerCase(), secondCity: city2.toLowerCase(), } } } What value can a developer expect when referencing o.js.secondCity? 
 

A. Undefined
B. ‘ new york ’
C. ‘ New York ’
D. An error

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Question # 32

 A class was written to represent items for purchase in an online store, and a second class Representing items that are on sale at a discounted price. THe constructor sets the name to the first value passed in. The pseudocode is below: Class Item { constructor(name, price) { … // ConstructorImplementation } } Class SaleItem extends Item { constructor (name, price, discount) { ...//Constructor Implementation } } There is a new requirement for a developer to implement a description method that will return a brief description for Item and SaleItem. Let regItem =new Item(‘Scarf’, 55); Let saleItem = new SaleItem(‘Shirt’ 80, -1); Item.prototype.description = function () { return ‘This is a ’ + this.name; console.log(regItem.description()); console.log(saleItem.description()); SaleItem.prototype.description = function () { return ‘This is a discounted ’ + this.name; } console.log(regItem.description()); console.log(saleItem.description()); What is the output when executing the code above ? 
 

A. This is a Scarf Uncaught TypeError:saleItem.description is not a function This is aScarf This is a discounted Shirt
B. This is a Scarf This is a Shirt This is a Scarf This is a discounted Shirt
C. This is a Scarf This is a Shirt This is a discounted Scarf This is a discounted Shirt
D. Thisis aScarf Uncaught TypeError: saleItem.description is not a function This is a Shirt This is a did counted Shirt

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Question # 33

Refer to the code below: Const resolveAfterMilliseconds = (ms) => Promise.resolve ( setTimeout (( => console.log(ms), ms )); Const aPromise = await resolveAfterMilliseconds(500); Const bPromise = await resolveAfterMilliseconds(500); Await aPromise, wait bPromise; What is the result of runningline 05? 
 

A. aPromise and bPromise run sequentially.
B. Neither aPromise or bPromise runs.
C. aPromise and bPromise run in parallel.
D. Only aPromise runs.

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Question # 34

A developer has a formatName function that takes two arguments, firstName and lastName and returns a string. They want to schedule the function to run once after five seconds. What is the correct syntax to schedule this function? 
 

A. setTimeout (formatName(), 5000, "John", "BDoe");
B. setTimeout (formatName('John', ‘'Doe'), 5000);
C. setTimout(() => { formatName("John', 'Doe') }, 5000);
D. setTimeout ('formatName', 5000, 'John", "Doe');

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Question # 35

is the output of line 02? 
 

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

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Question # 36

 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? 
 

A. Car 3 completed the race.
B. Car 1 crashed in the race.
C. Car 2 completed the race.
D. Race is cancelled.

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Question # 37

Why would a developer specify a package.jason as a developed forge instead of a
 dependency ? 
 

A. It is required by the application in production.
B. It is only needed for local development and testing.
C. Other requiredpackages depend on it for development.
D. It should be bundled when the package is published.

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Question # 38

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 notneed to verify how many times the method has been called. Which two test approaches describe the requirement? Choose 2 answers 
 

A. White box
B. Stubbing
C. Black box
D. Substitution

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Question # 39

A developer is creating a simple webpage with a button. When a userclicks this button for the first time, a message is displayed. The developer wrote the JavaScript code below, but something is missing. The message gets displayed every time a user clicks the button, instead of just the first time. 01 functionlisten(event) { 02 alert ( ‘Hey! I am John Doe’) ; 03 button.addEventListener (‘click’, listen); Which two code lines make this code work as required? Choose 2 answers 
 

A. On line 02, use event.first to test if it is the first execution.
B. On line 04, useevent.stopPropagation ( ),
C. On line 04, use button.removeEventListener(‘ click” , listen);
D. On line 06, add an option called once to button.addEventListener().

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Question # 40

Given the following code: Let x =null; console.log(typeof x); What is the output of the line 02? 
 

A. “Null”
B. “X”
C. “Object”
D. “undefined”

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