EMT Practice Test

1. Question Content...

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Question1: Which option is true about the strict mode in imported modules?

Question2: A developer has a web server running with Node.js. The command to start the web server is node server.js. The web server started having
latency issues. Instead of a one second turnaround for web requests, the developer now sees a five second turnaround.
Which command can the web developer run to see what the module is doing during the latency period?

Question3: A developer is setting up a Node,js server and is creating a script at the root of the source code, index,js, that will start the server when executed. The developer declares a variable that needs the folder location that the code executes from.
Which global variable can be used in the script?

Question4: A developer wrote a fizzbuzz function that when passed in a number, returns the
following:
● 'Fizz' if the number is divisible by 3.
● 'Buzz' if the number is divisible by 5.
● 'Fizzbuzz' if the number is divisible by both 3 and 5.
● Empty string if the number is divisible by neither 3 or 5.
Which two test cases will properly test scenarios for the fizzbuzz function?
Choose 2 answers

Question5: 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' ?

Question6: developer is trying to convince management that their team will benefit from using
Node.js for a backend server that they are going to create. The server will be a web server that
handles API requests from a website that the team has already built using HTML, CSS, and
JavaScript.
Which three benefits of Node.js can the developer use to persuade their manager?
Choose 3 answers:

Question7: 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.'?

Question8: 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?

Question9: Refer to the code below:

What is the value of result when the code executes?

Question10: 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

Question11: 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?

Question12: Universal Container(UC) just launched a new landing page, but users complain that the
website is slow. A developer found some functions that cause this problem. To verify this, the
developer decides to do everything and log the time each of these three suspicious functions
consumes.
console.time('Performance');
maybeAHeavyFunction();
thisCouldTakeTooLong();
orMaybeThisOne();
console.endTime('Performance');
Which function can the developer use to obtain the time spent by every one of the three
functions?

Question13: Refer of the string below:
Const str = 'sa;esforce'=;
Which two statement result in the word 'Sale'?
Choose 2 answers

Question14: 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?

Question15: 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)

Question16: Given the code below:
const delay = sync delay => {
Return new Promise((resolve, reject) => {
setTimeout (resolve, delay);});};
const callDelay =async () =>{
const yup =await delay(1000);
console.log(1);
What is logged to the console?

Question17: 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 ?

Question18: 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?

Question19: Refer to code below:
console.log(0);
setTimeout(() => (
console.log(1);
});
console.log(2);
setTimeout(() => {
console.log(3);
), 0);
console.log(4);
In which sequence will the numbers be logged?

Question20: Which two console logs output NaN?
Choose 2 answers | |

Question21: Given two expressions var1 and var2. What are two valid ways to return the logical AND
of the two expressions and ensure it is data type Boolean ?
Choose 2 answers:

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: Refer to the code below:
let sayHello = () => {
console.log ('Hello, world!');
};
Which code executes sayHello once, two minutes from now?

Question24: Refer to the code:

Given the code above, which three properties are set pet1?
Choose 3 answers:

Question25: Refer to the code snippet below:
Let array = [1, 2, 3, 4, 4, 5, 4, 4];
For (let i =0; i < array.length; i++){
if (array[i] === 4) {
array.splice(i, 1);
}
}
What is the value of the array after the code executes?

Question26: Given the requirement to refactor the code above to JavaScript class format, which class
definition is correct?

A)

B)

C)

D)

Question27: 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 events and
callbacks to start the servers
Which code should be inserted at the line 03 to set up an event and start the web server ?

Question28: A developer wants to iterate through an array of objects and count the objects and count
the 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 02
02 //missing line 03
04 ). 0);
Which missing lines 02 and 03 return the correct count?

Question29: 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.

Question30: A developer uses a parsed JSON string to work with user information as in the block below:
01 const userInformation ={
02 " id " : "user-01",
03 "email" : "[email protected]",
04 "age" : 25
Which two options access the email attribute in the object?
Choose 2 answers

Question31: 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?

Question32: Given the following code:

is the output of line 02?

Question33: 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?

Question34: 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:

Question35: Which function should a developer use to repeatedly execute code at a fixed interval ?

Question36: 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?

Question37: Which two code snippets show working examples of a recursive function?
Choose 2 answers

Question38: 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?

Question39: A developer wants to create an object from a function in the browser using the code
below:
Function Monster() { this.name = 'hello' };
Const z = Monster();
What happens due to lack of the new keyword on line 02?

Question40: Which three actions can be using the JavaScript browser console?
Choose 3 answers:

Question41: 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 ?

Question42: 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."?

Question43: 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);

Question44: 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?

Question45: Refer to the code below:

Which value can a developer expect when referencing country,capital,cityString?

Question46: Refer to the following object:
const cat ={
firstName: 'Fancy',
lastName: ' Whiskers',
Get fullName() {
return this.firstName + ' ' + this.lastName;
}
};
How can a developer access the fullName property for cat?

Question47: Which statement accurately describes an aspect of promises?

Question48: 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?

Question49: 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?

Question50: A test has a dependency on database.query. During the test the dependency is replaced
with an object called database with the method, query, that returns an array. The
developer needs to verify how many times the method was called and the arguments
used each time.
Which two test approaches describe the requirement?
Choose 2 answers

Question51: A developer at Universal Containers creates a new landing page based on HTML, CSS, and
JavaScript TO ensure that visitors have a good experience, a script named personaliseContext
needs to be executed when the webpage is fully loaded (HTML content and all related files ), in
order to do some custom initialization.
Which statement should be used to call personalizeWebsiteContent based on the above
business requirement?

Question52: 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?

Question53: Given the expressions var1 and var2, what are two valid ways to return the concatenation of the two expressions and ensure it is string? Choose 2 answers

Question54: Consider type coercion, what does the following expression evaluate to?
True + 3 + '100' + null

Question55: developer removes the HTML class attribute from the checkout button, so now it is
simply:
<button>Checkout</button>.
There is a test to verify the existence of the checkout button, however it looks for a button with
class= "blue". The test fails because no such button is found.
Which type of test category describes this test?

Question56: Given the code below:
const copy = JSON.stringify([ new String(' false '), new Bollean( false ), undefined ]);
What is the value of copy?

Question57: Given the following code:
Let x =('15' + 10)*2;
What is the value of a?

Question58: A developer wants to leverage a module to print a price in pretty format, and has imported a method as shown below:
Import printPrice from '/path/PricePrettyPrint.js';
Based on the code, what must be true about the printPrice function of the PricePrettyPrint module for this import to work ?

Question59: 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?

Question60: myArraym can have one level, two levels, or more levels.
Which statement flattens myArray when it can be arbitrarily nested?