JavaScript-Developer-I Sample Questions Answers

The developer wants to test this code:

Const toNumber =(strOrNum) => strOrNum;

Which two tests are most accurate for this code?

Choose 2 answers

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)

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?

In which situation should a developer include a try .. catch block around their function call ?

Which statement accurately describes an aspect of promises?

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

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?

The developer has a function that prints “Hello” to an input name. To test this, thedeveloper created a function that returns “World”. However the following snippet does not print “ Hello World”.

What can the developer do to change the code to print “Hello World” ?

Refer to the code below:

Const pi = 3.1415326,

What is the data type of pi?

Refer to the following code:

What is the value of output on line 11?

Given the JavaScript below:

01 function filterDOM (searchString) {

02 const parsedSearchString = searchString && searchString.toLowerCase() ;

03 document.quesrySelectorAll(‘ .account’ ) . forEach(account => (

04 const accountName = account.innerHTML.toLOwerCase();

05 account. Style.display = accountName.includes(parsedSearchString) ? /*Insert

code*/;

06 )};

07 }

Which code should replace the placeholder comment on line 05 to hide accounts that do

not match the search string?

A developer wants to create an object from a function in the browser using the code below.

What happens due to the lack of the mm keyword on line 02?

A developer is leading the creation of a new web server for their team that will fulfill API requests from an existing client.

The team wants a web server that runs on Node.Js, and they want to use the new web framework Minimalist.Js. The lead developer wants to advocate for a more seasoned back-end framework that already has a community around it.

Which two frameworks could the lead developer advocate for?

Choose 2 answers

Which javascript methods can be used to serialize an object into a string and deserialize

a JSON string into an object, respectively?

Consider type coercion, what does the following expression evaluate to?

True + 3 + ‘100’ + null

Refer to the code below:

Let textValue = ’1984’;

Which code assignment shows a correct way to convert this string to an integer?

Given the following code:

Let x =(‘15’ + 10)*2;

What is the value of a?

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.

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

Refer to the code below:

Line 05 causes an error.

What are the values of greeting and salutation once code completes?

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 business requirement ?

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:

Display 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 to make this code work as expected?

myArraym can have one level, two levels, or more levels.

Which statement flattens myArray when it can be arbitrarily nested?

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

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?

Refer to the code below:

What is the result when the Promise in the execute function is rejected?

Refer the following code

what is the value of array after code executes?

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

A developer has an ErrorHandler module that contains multiple functions.

What kind of export be leverages so that multiple functions can be used?

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?