JavaScript-Developer-I Exam Questions

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

A.

“Null”

B.

“X”

C.

“Object”

D.

“undefined”

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.

Option

B.

Option

C.

Option

D.

Option

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

A.

The developer missed the option --add when adding the dependency.

B.

The developer added the dependency as a dev dependency, and
NODE_ENV Is set to production.

C.

The developer missed the option --save when adding the dependency.

D.

The developer added the dependency as a dev dependency, and
NODE_ENV is set to production.

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.”?

A.

document.querySelectorAll(‘$main $TONY’).innerHTML = ’ Mr. T. ’;

B.

document.querySelector(‘$main li:second-child’).innerHTML = ’ Mr. T. ’;

C.

document.querySelector(‘$main li.Tony’).innerHTML = ’ Mr. T. ’;

D.

document.querySelector(‘$main li:nth-child(2)’),innerHTML = ’ Mr. T. ’;

Refer to the code below:
Const searchTest = ‘Yay! Salesforce is amazing!” ;
Let result1 = searchText.search(/sales/i);
Let result 21 = searchText.search(/sales/i);
console.log(result1);
console.log(result2);
After running this code, which result is displayed on the console?

A.

> true > false B. > 5 >undefined

B.

> 5 > -1

C.

> 5 > 0

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 ?

A.

[title: “javaScript”] [title: “javaScript”]

B.

{author: “Robert”, title: “javaScript}
Undefined

C.

{author: “Robert”, title: “javaScript}
{author: “Robert”, title: “javaScript}

D.

{author: “Robert”}
{author: “Robert”, title: “javaScript}

A developer wants to define a function log to be used a few times on a single-file
JavaScript script.
01 // Line 1 replacement
02 console.log('"LOG:', logInput);
03 }
Which two options can correctly replace line 01 and declare the function for use?
Choose 2 answers

A.

function leg(logInput) {

B.

const log(loginInput) {

C.

const log = (logInput) => {

D.

function log = (logInput) {

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?

A.

10

B.

Nan

C.

5

D.

Undefined

developer uses the code below to format a date.

let timerId = setTimeout (timedFunction, 1000);
Which statement allows a developer to cancel the scheduled timed function?

A.

A. removeTimeout(timedFunction);

B.

removeTimeout(timerId);

C.

clearTimeout(timerId);

D.

clearTimeout(timedFunction);

let timerId = setTimeout (timedFunction, 1000);
Which statement allows a developer to cancel the scheduled timed function?

A.

removeTimeout(timedFunction);

B.

removeTimeout(timerId);

C.

clearTimeout(timerId);

D.

clearTimeout(timedFunction);