EMT Practice Test

1. Question Content...


Question List

Question1: Which three statements are true about promises ?
Choose 3 answers

Question2: 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);

Question3: 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?

Question4: 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?

Question5: 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?

Question6: 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?

Question7: Refer to the following code:
01 function Tiger(){
02 this.Type = 'Cat';
03 this.size = 'large';
04 }
05
06 let tony = new Tiger();
07 tony.roar = () =>{
08 console.log('They\'re great1');
09 };
10
11 function Lion(){
12 this.type = 'Cat';
13 this.size = 'large';
14 }
15
16 let leo = new Lion();
17 //Insert code here
18 leo.roar();
Which two statements could be inserted at line 17 to enable the function call on line 18?
Choose 2 answers.

Question8: Which two console logs output NaN?
Choose 2 answers | |

Question9: Which two console logs outputs NaN ?
Choose 2 answers

Question10: 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 turn around 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?

Question11: 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?

Question12: 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

Question13: 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?

Question14: Refer to the code below:
Let textValue = '1984';
Which code assignment shows a correct way to convert this string to an integer?

Question15: Which three browser specific APIs are available for developers to persist data between page loads ?
Choose 3 answers

Question16: A developer has code that calculates a restaurant bill, but generates incorrect answers while testing the code:
function calculateBill ( items ) {
let total = 0;
total += findSubTotal(items);
total += addTax(total);
total += addTip(total);
return total;
}
Which option allows the developer to step into each function execution within calculateBill?

Question17: 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 ?

Question18: 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 . . .

Question19: 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 ?

Question20: Which statement parses successfully?

Question21: Refer to the code below:
Const pi = 3.1415326,
What is the data type of pi?

Question22: 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?

Question23: Refer to code below:
Let a ='a';
Let b;
// b = a;
console.log(b);
What is displayed when the code executes?

Question24: 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:

Question25: Which javascript methods can be used to serialize an object into a string and deserialize a JSON string into an object, respectively?

Question26: Which code statement correctly retrieves and returns an object from localStorage?

Question27: A developer wrote the following code:
01 let X = object.value;
02
03 try {
04 handleObjectValue(X);
05 } catch (error) {
06 handleError(error);
07 }
The developer has a getNextValue function to execute after handleObjectValue(), but does not want to execute getNextValue() if an error occurs.
How can the developer change the code to ensure this behavior?

Question28: What is the result of the code block?

Question29: Which option is a core Node,js module?

Question30: The developer wants to test this code:
Const toNumber =(strOrNum) => strOrNum;
Which two tests are most accurate for this code?
Choose 2 answers

Question31: 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?

Question32: Refer to the expression below:
Let x = ('1' + 2) == (6 * 2);
How should this expression be modified to ensure that evaluates to false?

Question33: developer publishes a new version of a package with new features that do not break backward compatibility. The previous version number was 1.1.3.
Following semantic versioning format, what should the new package version number be?

Question34: 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' ?

Question35: 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?

Question36: 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

Question37: A developer wants to set up a secure web server with Node.js. The developer creates a directory locally called app-server, and the first file is app-server/index.js Without using any third-party libraries, what should the developer add to index.js to create the secure web server?

Question38: 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 ?

Question39: Refer to the code below:
let sayHello = () => {
console.log ('Hello, world!');
};
Which code executes sayHello once, two minutes from now?

Question40: Consider type coercion, what does the following expression evaluate to?
True + 3 + '100' + null

Question41: Considering type coercion, what does the following expression evaluate to?
True + '13' + NaN

Question42: 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

Question43: Refer to following code block:
Let array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,];
Let output =0;
For (let num of array){
if (output >0){
Break;
}
if(num % 2 == 0){
Continue;
}
Output +=num;
What is the value of output after the code executes?

Question44: Which statement accurately describes the behaviour of the async/ await keyworks ?

Question45: A developer is required to write a function that calculates the sum of elements in an array but is getting undefined every time the code is executed. The developer needs to find what is missing in the code below.
Const sumFunction = arr => {
Return arr.reduce((result, current) => {
//
Result += current;
//
), 10);
);
Which option makes the code work as expected?

Question46: 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

Question47: 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

Question48: 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 ?

Question49: 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?

Question50: Given the following code:
Let x =('15' + 10)*2;
What is the value of a?

Question51: Refer to the code below:

Line 05 causes an error.
What are the values of greeting and salutation once code completes?

Question52: 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?

Question53: 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

Question54: 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 ?

Question55: 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

Question56: 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 ?