EMT Practice Test

1. Question Content...

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Question1: At Universal Containers, every team has its own way of copying JavaScript objects. The code Snippet shows an implementation from one team:
Function Person() {
this.firstName = "John";
this.lastName = 'Doe';
This.name =() => (
console.log('Hello $(this.firstName) $(this.firstName)');
)}
Const john = new Person ();
Const dan = JSON.parse(JSON.stringify(john));
dan.firstName ='Dan';
dan.name();
What is the Output of the code execution?

Question2: A developer creates a class that represents a blog post based on the requirement that a Post should have a body author and view count.
The Code shown Below:
Class Post {
// Insert code here
This.body =body
This.author = author;
this.viewCount = viewCount;
}
}
Which statement should be inserted in the placeholder on line 02 to allow for a variable to be set to a new instanceof a Post with the three attributes correctly populated?

Question3: A developer is creating a simple webpage with a button. When a user clicks 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 function listen(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

Question4: developer creates a new web server that uses Node.js. It imports a server library that uses events and callbacks for handling server functionality.
The server library is imported with require and is made available to the code by a variable named server. The developer wants to log any issues that the server has while booting up.
Given the code and the information the developer has, which code logs an error at boost with an event?

Question5: In the browser, the window object is often used to assign variables that require the broadest scope in an application Node.js application does not have access to the window object by default.
Which two methods are used to address this ?
Choose 2 answers

Question6: A developer is asked to fix some bugs reported by users. To do that, the developer adds a breakpoint for debugging.
Function Car (maxSpeed, color){
This.maxspeed =masSpeed;
This.color = color;
Let carSpeed = document.getElementById(' CarSpeed');
Debugger;
Let fourWheels =new Car (carSpeed.value, 'red');
When the code execution stops at the breakpoint on line 06, which two types of information are available in the browser console ?
Choose 2 answers:

Question7: Which function should a developer use to repeatedly execute code at a fixed interval ?

Question8: Refer to the code below:
Let inArray =[ [ 1, 2 ] , [ 3, 4, 5 ] ];
Which two statements result in the array [1, 2, 3, 4, 5] ?
Choose 2 answers

Question9: Refer to the code below:
let car1 = new Promise((_ ,reject)=> setTimeout(reject,2000,"Car1 crashed in")); let car2 = new Promise(resolve => setTimeout(resolve,1500,"Car2 completed")); let car3 = new Promise(resolve => setTimeout(resolve,3000,"Car3 completed")); Promise.race([car1,car2,car3])
.then(value=>{
let result = `${value} the race.`;
}).catch(err=>{
console.log('Race is cancelled.',err);
});
What is the value of result when promise.race execues?

Question10: Cloud Kicks has a class to represent items for sale in an online store, as shown below:
Class Item{
constructor (name, price){
this.name = name;
this.price = price;
}
formattedPrice(){
return 's' + String(this.price);}}
A new business requirement comes in that requests a ClothingItem class that should have all of the properties and methods of the Item class but will also have properties that are specific to clothes.
Which line of code properly declares the clothingItem class such that it inherits from Item?

Question11: 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)

Question12: Which code statement below correctly persists an objects in local Storage ?

Question13: Refer to the code below:
Const pi = 3.1415326,
What is the data type of pi?

Question14: Which two console logs output NaN?
Choose 2 answers | |

Question15: Refer to the code below:
new Promise((resolve, reject) => {
const fraction = Math.random();
if( fraction >0.5) reject("fraction > 0.5, " + fraction);
resolve(fraction);
})
.then(() =>console.log("resolved"))
.catch((error) => console.error(error))
.finally(() => console.log(" when am I called?"));

When does Promise.finally on line 08 get called?

Question16: After user acceptance testing, the developer is asked to change the webpage background based on user's location. This change was implemented and deployed for testing.
The tester reports that the background is not changing, however it works as required when viewing on the developer's computer.
Which two actions will help determine accurate results?
Choose 2 answers

Question17: Given the code below:

Which method can be used to provide a visual representation of the list of users and to allow sorting by the name or email attribute?

Question18: 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 ?

Question19: Refer to the following code:

What is the output of line 11?

Question20: Refer to the following object.

How can a developer access the fullName property for dog?

Question21: Refer to the following code:

Question22: 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?

Question23: 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 be displayed in the console.
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 make this code work as expected?

Question24: 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?

Question25: Given the code below:

What is logged to the console'

Question26: The developer wants to test the array shown:
const arr = Array(5).fill(0)
Which two tests are the most accurate for this array ?
Choose 2 answers:

Question27: Refer to the following code:

Which statement should be added to line 09 for the code to display 'The boat has a capacity of 10 people?

Question28: Which three browser specific APIs are available for developers to persist data between page loads ?
Choose 3 answers

Question29: Refer to the following code block:

What is the console output?

Question30: Refer to the following code:
function test (val) {
If (val === undefined) {
return 'Undefined values!' ;
}
if (val === null) {
return 'Null value! ';
}
return val;
}
Let x;
test(x);
What is returned by the function call on line 13?

Question31: A developer creates a generic function to log custom messages in the console. To do this, the function below is implemented.
01 function logStatus(status){
02 console./*Answer goes here*/{'Item status is: %s', status};
03 }
Which three console logging methods allow the use of string substitution in line 02?

Question32: 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?

Question33: Teams at Universal Containers (UC) work on multiple JavaScript projects at the same time.
UC is thinking about reusability and how each team can benefit from the work of others.
Going open-source or public is not an option at this time.
Which option is available to UC with npm?

Question34: Which statement parses successfully?

Question35: Refer to the following array:
Let arr = [ 1,2, 3, 4, 5];
Which three options result in x evaluating as [3, 4, 5] ?
Choose 3 answers.

Question36: 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?

Question37: 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:

Question38: Given the following code:

What will be the first four numbers logged?

Question39: Refer to the following code:
Let sampleText = 'The quick brown fox jumps';
A developer needs to determine if a certain substring is part of a string.
Which three expressions return true for the given substring ?
Choose 3 answers

Question40: Refer to the code below:
const car = {
price:100,
getPrice:function(){
return this.price;
}
};
const customCar = Object.create(car);
customCar.price = 70;
delete customCar.price;const result = customCar.getPrice();
What is the value of result after the code executes?

Question41: Which option is a core Node,js module?

Question42: bar, awesome is a popular JavaScript module. the versions publish to npm are:

Teams at Universal Containers use this module in a number of projects. A particular project has the package, json definition below.

A developer runs this command: npm install.
Which version of bar .awesome is installed?

Question43: Why would a developer specify a package.jason as a developed forge instead of a dependency ?

Question44: Refer to code below:
function Person() {
this.firstName = 'John';
}
Person.prototype ={
Job: x => 'Developer'
};
const myFather = new Person();
const result =myFather.firstName + ' ' + myFather.job();
What is the value of the result after line 10 executes?

Question45: 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 about recordId.
Which two options could a developer insert at the placeholder in line 02 to achieve this?
Choose 2 answers

Question46: 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 be displayed in the console.
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?

Question47: myArraym can have one level, two levels, or more levels.
Which statement flattens myArray when it can be arbitrarily nested?

Question48: Given the code below:
const copy = JSON.stringify([ new String(' false '), new Bollean( false ), undefined ]); What is the value of copy?

Question49: Universal Containers recently launched its new landing page to host a crowd-funding campaign. The page uses an external library to display some third-party ads. Once the page is fully loaded, it creates more than 50 new HTML items placed randomly inside the DOM, like the one in the code below:

All the elements includes the same ad-library-item class, They are hidden by default, and they are randomly displayed while the user navigates through the page.

Question50: Given the following code:

is the output of line 02?

Question51: Given the code below:
Which three code segments result in a correct conversion from number to string? Choose 3 answers

Question52: A developer has the function, shown below, that is called when a page loads.

Where can the developer see the log statement after loading the page in the browser?

Question53: Given the following code:
document.body.addEventListener(' click ', (event) => {
if (/* CODE REPLACEMENT HERE */) {
console.log('button clicked!');
)
});
Which replacement for the conditional statement on line 02 allows a developer to correctly determine that a button on page is clicked?

Question54: 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

Question55: Refer to the code below:
Function Person(firstName, lastName, eyecolor) {
this.firstName =firstName;
this.lastName = lastName;
this.eyeColor = eyeColor;
}
Person.job = 'Developer';
const myFather = new Person('John', 'Doe');
console.log(myFather.job);
What is the output after the code executes?

Question56: A developer has two ways to write a function:
Option A:
function Monster() {
This.growl = () => {
Console.log ("Grr!");
}
}
Option B:
function Monster() {};
Monster.prototype.growl =() => {
console.log("Grr!");
}
After deciding on an option, the developer creates 1000 monster objects.
How many growl methods are created with Option A Option B?

Question57: Which statement accurately describes an aspect of promises?

Question58: A developer wants to create an object from a function in the browser using the code below.

What happens due to the lack of the mm keyword on line 02?

Question59: 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?

Question60: Refer to the following code that performs a basic mathematical operation on a provided input:
function calculate(num) {
Return (num +10) / 3;
}
How should line 02 be written to ensure that x evaluates to 6 in the line below?
Let x = calculate (8);

Question61: Which two console logs outputs NaN ?
Choose 2 answers

Question62: Refer to the HTML below:
<div id="main">
<ul>
<li>Leo</li>
<li>Tony</li>
<li>Tiger</li>
</ul>
</div>
Which JavaScript statement results in changing " Tony" to "Mr. T."?

Question63: Refer to the code snippet:
Function getAvailabilityMessage(item) {
If (getAvailability(item)){
Var msg ="Username available";
}
Return msg;
}
A developer writes this code to return a message to user attempting to register a new username. If the username is available, variable.
What is the return value of msg hen getAvailabilityMessage ("newUserName" ) is executed and getAvailability("newUserName") returns false?

Question64: Refer the following code

what is the value of array after code executes?

Question65: Refer to the code below:
Function changeValue(obj) {
Obj.value = obj.value/2;
}
Const objA = (value: 10);
Const objB = objA;
changeValue(objB);
Const result = objA.value;
What is the value of result after the code executes?

Question66: 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

Question67: 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) {
... // Constructor Implementation
}
}
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 ?

Question68: Refer to HTML below:
<div id ="main">
<div id = " card-00">This card is smaller.</div>
<div id = "card-01">The width and height of this card is determined by its contents.</div>
</div>
Which expression outputs the screen width of the element with the ID card-01?

Question69: Refer to the code below:

What is the value of result after line 10 executes?

Question70: 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?

Question71: developer uses the code below to format a date.

After executing, what is the value of formattedDate?

Question72: A developer implements and calls the following code when an application state change occurs:
Const onStateChange =innerPageState) => {
window.history.pushState(newPageState, ' ', null);
}
If the back button is clicked after this method is executed, what can a developer expect?

Question73: Refer to the code below
let inArray = [[1,2],[3,4,5]];
which two statements results in the array [1,2,3,4,5]?
choose 2 answer

Question74: Given the requirement to refactor the code above to JavaScript class format, which class definition is correct?

A)

B)

C)

D)

Question75: Which three options show valid methods for creating a fat arrow function?
Choose 3 answers

Question76: Which three statements are true about promises ?
Choose 3 answers

Question77: Which two options are core Node.js modules?
Choose 2 answers

Question78: A developer is leading the creation of a new browser application that will serve a single page application. The team wants to use a new web framework Minimalsit.js. The Lead developer wants to advocate for a more seasoned web framework that already has a community around it.
Which two frameworks should the lead developer advocate for?
Choose 2 answers

Question79: 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 running line 05?

Question80: Given the following code:
Counter = 0;
const logCounter = () => {
console.log(counter);
);
logCounter();
setTimeout(logCOunter, 1100);
setInterval(() => {
Counter++
logCounter();
}, 1000);
What is logged by the first four log statements?

Question81: Which javascript methods can be used to serialize an object into a string and deserialize a JSON string into an object, respectively?

Question82: GIven a value, which three options can a developer use to detect if the value is NaN?
Choose 3 answers !

Question83: Refer to code below:
Function muFunction(reassign){
Let x = 1;
var y = 1;
if( reassign ) {
Let x= 2;
Var y = 2;
console.log(x);
console.log(y);}
console.log(x);
console.log(y);}
What is displayed when myFunction(true) is called?

Question84: 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 . . .

Question85: Refer to HTML below:
<p> The current status of an Order: <span id ="status"> In Progress </span> </p>.
Which JavaScript statement changes the text 'In Progress' to 'Completed' ?

Question86: Refer to code below:
Const objBook = {
Title: 'Javascript',
};
Object.preventExtensions(objBook);
Const newObjBook = objBook;
newObjectBook.author = 'Robert';
What are the values of objBook and newObjBook respectively ?