EMT Practice Test

1. Question Content...

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Question1: 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?

Question2: Which two console logs outputs NaN ?
Choose 2 answers

Question3: Refer to the following code block:
class Animal{
constructor(name){
this.name = name;
}
makeSound(){
console.log(`${this.name} is making a sound.`)
}
}
class Dog extends Animal{
constructor(name){
super(name)
this.name = name;
}
makeSound(){
console.log(`${this.name} is barking.`)
}
}
let myDog = new Dog('Puppy');
myDog.makeSound();
What is the console output?

Question4: 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?

Question5: 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?

Question6: A developer is setting up a new Node.js server with a client library that is built using events and callbacks.
The library:
* Will establish a web socket connection and handle receipt of messages to the server
* Will be imported with require, and made available with a variable called we.
The developer also wants to add error logging if a connection fails.
Given this info, which code segment shows the correct way to set up a client with two events that listen at execution time?

Question7: Refer to the expression below:
Let x = ('1' + 2) == (6 * 2);
How should this expression be modified to ensure that evaluates to false?

Question8: 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' ?

Question9: 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?

Question10: Considering the implications of 'use strict' on line 04, which three statements describe the execution of the code?
Choose 3 answers

Question11: 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?

Question12: Refer to the 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 missing code for the code to display 'The truck 123AB has a weight of 5000lb.

Question13: 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?

Question14: 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 ?

Question15: A developer writers the code below to calculate the factorial of a given number.
Function factorial(number) {
Return number + factorial(number -1);
}
factorial(3);
What is the result of executing line 04?

Question16: Refer to the code below:

Which replacement for the conditional statement on line 02 allows a developer to correctly determine that a specific element, myElement on the page had been clicked?

Question17: 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?

Question18: 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?

Question19: 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?

Question20: 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?

Question21: A developer receives a comment from the Tech Lead that the code given below has error:
const monthName = 'July';
const year = 2019;
if(year === 2019) {
monthName = 'June';
}
Which line edit should be made to make this code run?

Question22: A developer is wondering whether to use, Promise.then or Promise.catch, especially when a Promise throws an error?
Which two promises are rejected?
Which 2 are correct?

Question23: Refer to the code below:

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

Question24: Given the code below:
const copy = JSON.stringify([ new String(' false '), new Bollean( false ), undefined ]); What is the value of copy?

Question25: 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?

Question26: developer wants to use a module named universalContainersLib and them call functions from it.
How should a developer import every function from the module and then call the fuctions foo and bar ?

Question27: 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:

Question28: A developer has the function, shown below, that is called when a page loads.
function onload() {
console.log("Page has loaded!");
}
Where can the developer see the log statement after loading the page in the browser?

Question29: 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?

Question30: 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 number in the array, The test passes:
Let res = sum2([1, 2, 3 ]) ;
console.assert(res === 6 );
Res = sum3([ 1, 2, 3, 4]);
console.assert(res=== 6);
A different developer made changes to the behavior of sum3 to instead sum all of the numbers present in the array. The test passes:
Which two results occur when running the test on the updated sum3 function ?
Choose 2 answers

Question31: 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.'?

Question32: Refer to the string below:
const str = 'Salesforce';
Which two statements result in the word 'Sales'?
Choose 2 answers

Question33: Refer to the string below.
Const str='Salesforce';
Which two statements results in the word 'Sales'?

Question34: Refer to the following code:

What is the value of output on line 11?

Question35: 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

Question36: A team that works on a big project uses npm to deal with projects dependencies.
A developer added a dependency does not get downloaded when they execute npm install.
Which two reasons could be possible explanations for this?
Choose 2 answers

Question37: 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?

Question38: Given the following code:
Let x =null;
console.log(typeof x);
What is the output of the line 02?

Question39: 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?

Question40: 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?

Question41: Consider type coercion, what does the following expression evaluate to?
True + 3 + '100' + null

Question42: Given the code below:

What is logged to the console'

Question43: 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?

Question44: 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?

Question45: 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?

Question46: Which two console logs output NaN?
Choose 2 answers | |

Question47: 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?

Question48: A developer implements a function that adds a few values.
Function sum(num) {
If (num == undefined) {
Num =0;
}
Return function( num2, num3){
If (num3 === undefined) {
Num3 =0 ;
}
Return num + num2 + num3;
}
}
Which three options can the developer invoke for this function to get a return value of 10 ?
Choose 3 answers

Question49: Given the requirement to refactor the code above to JavaScript class format, which class definition is correct?

A)

B)

C)

D)

Question50: Refer the following code

what is the value of array after code executes?

Question51: 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 ?

Question52: 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 . . .

Question53: 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?

Question54: Refer of the string below:
Const str = 'sa;esforce'=;
Which two statement result in the word 'Sale'?
Choose 2 answers

Question55: Given the HTML below:

Which statement adds the priority-account css class to the Applied Shipping row?

Question56: GIven a value, which three options can a developer use to detect if the value is NaN?
Choose 3 answers !

Question57: 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:

Question58: Refer to the code below:
<html lang="en">
<table onclick="console.log(Table log');">
<tr id="row1">
<td>Click me!</td>
</tr>
<table>
<script>
function printMessage(event) {
console.log('Row log');
}
Let elem = document.getElementById('row1');
elem.addEventListener('click', printMessage, false);
</script>
</html>
Which code change should be made for the console to log only Row log when 'Click me! ' is clicked?

Question59: Refer to the following array:
Let arr = [1, 2, 3, 4, 5];
Which three options result in x evaluating as [1, 2]?
Choose 3 answer

Question60: 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?

Question61: 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?

Question62: 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?

Question63: 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

Question64: 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?

Question65: 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?

Question66: Refer to the code below:
function foo () {
const a =2;
function bat() {
console.log(a);
}
return bar;
}
Why does the function bar have access to variable a ?

Question67: 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 ?

Question68: A developer at Universal Containers is creating their new landing page based on HTML, CSS, and JavaScript. The website includes multiple external resources that are loaded when the page is opened.
To ensure that visitors have a good experience, a script named personalizeWebsiteContent needs to be executed when the webpage Is loaded and there Is no need to wait for the resources to be available.
Which statement should be used to call personalizeWebsiteContent based on the above business requirement?

Question69: Refer to the following code:
<html lang="en">
<body>
<div onclick = "console.log('Outer message') ;">
<button id ="myButton">CLick me<button>
</div>
</body>
<script>
function displayMessage(ev) {
ev.stopPropagation();
console.log('Inner message.');
}
const elem = document.getElementById('myButton');
elem.addEventListener('click' , displayMessage);
</script>
</html>
What will the console show when the button is clicked?

Question70: Refer to the code declarations below:

Which three expressions return the string JavaScript?
Choose 3 answers

Question71: Which statement can a developer apply to increment the browser's navigation history without a page refresh?
Which statement can a developer apply to increment the browser's navigation history without a page refresh?