IT Certification Exam Questions & Answers

Q30. Refer to the following array:
Let arr1 = [ 1,2, 3, 4, 5 ];

Which two lines of code result in a second array, arr2 being created such that arr2 is not a reference to arr1?

Q31. 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 `ws`.
The developer also wants to add error logging if a connection fails.
Given this information, which code segment shows the correct way to set up a client with two events that listen at execution time?

Q32. A developer creates an object where its properties should be immutable and prevent properties from being added or modified.
Which method should be used to execute this businessrequirement ?

Q33. Correct implementation of try…catch for countsDeep():

Q34. Refer to the code below:
“`html
<html>
<body>
<div id=”logo”>Hello Logo!</div>
<button id=”test”>Click me</button>
</body>
<script>
function printMessage() {
console.log(‘This is a test message’);
}
let el = document.getElementById(‘test’);
el.addEventListener(“click”, printMessage, false);
</script>
</html>

Q35. Which code statement below correctly persists an objects inlocal Storage ?

Q36. Function to test:
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 this function?

Q37. A developer has an ErrorHandler module that contains multiple functions.
What kind of export should be leveraged so that multiple functions can be used?

Q38. Refer to the following object:
const dog = {
firstName: ‘Beau’,
lastName: ‘Boo’,
get fullName() {
return this.firstName + ‘ ‘ + this.lastName;
}
};
How can a developer access the fullName property for dog?

Q39. 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.
01 const sumFunction = arr => {
02 return arr.reduce((result, current) => {
03 //
04 result += current;
05 //
06 }, 10);
07 };
Which line replacement makes the code work as expected?

Q40. Given the JavaScript below:
function onLoad() {
console.log(“Page has loaded!”);
}
Where can the developer see the log statement after loading the page in the browser?

Q41. Refer to the code below:
<html lang=”en”>
<table onclick=”console.log(Table log’);”>
<tr id=”row1″>
<td>Click me!</td>
</tr>
<table>
<script>
functionprintMessage(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?

Q42. 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

Q43. Given a value, which two options can a developer use to detect if the value is NaN?

Q44. A developer tries to retrieve all cookies, then sets a certain key value pair in the cookie. These statements are used:

What is the behavior?

Q45. 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.
01 const sumFunction = arr => {
02 return arr.reduce((result, current) => {
03 //
04 result += current;
05 //
06 }, 10);
07 };
Which line replacement makes the code work as expected?

Q46. Given the code below:
let numValue = 1982;
Which three code segments result in a correct conversion from number to string?

Q47. 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 “Leo” to “The Lion”?

Q48. 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?

Q49. Code:
01 let array = [1, 2, 3, 4, 4, 5, 4, 4];
02 for (let i = 0; i < array.length; i++) {
03 if (array[i] === 4) {
04 array.splice(i, 1);
05 i–;
06 }
07 }
What is the value of array after execution?