JAVASCRIPT-DEVELOPER-I Online Practice Questions and Answers

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 array after the code executes?

A. Option A

B. Option B

C. Option C

D. Option D

A developer uses a parsed JSON string to work with user information as in the block below:

01 const user Information ={

02 " id " : "user-01",

03 "email" : "[email protected]",

04 "age" : 25

Which two options access the email attribute in the object?

Choose 2 answers

A. userInformation("email")

B. userInformation.get("email")

C. userInformation.email

D. userInformation(email)

myArraym canhave one level, two levels, or more levels. Which statement flattens myArray when it can be arbitrarily nested?

A. myArray. reduce ((prev, curr) => prev.concat(curr) [ ]);

B. myArray. join (","). split (",");

C. [ ] .concat {. . .myArray) ;

D. myArray.flat(Infinity);

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 tolack of the new keyword on line 02?

A. The z variable is assigned the correct object.

B. The z variable is assigned the correct object but this.name remains undefined.

C. Window.name is assigned to `hello' and the variable z remains undefined.

D. Window.mis assigned the correct object.

Refer to the code below:

Let str = `javascript';

Str[0] = `J';

Str[4] = 'S';

After changing the stringindex values, the value of str is `javascript'. What is the reason

for this value:

A. Non-primitive values are mutable.

B. Non-primitive values are immutable.

C. Primitive values are mutable.

D. Primitive values are immutable.

Given the code below:

01 function GameConsole (name) {

02 this.name = name;

03 }

05 GameConsole.prototype.load = function(gamename) {

06 console.log( ` $(this.name) is loading agame : $(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 cartridgegame: Super Monic 3x Force . . .

A. Console16bit.prototype.load(gamename) = function() {

B. Console16bit.prototype.load = function(gamename) {

C. Console16bit = Object.create(GameConsole.prototype).load = function (gamename) {

D. Console16bit.prototype.load(gamename) {

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 ?

A. productSKU = productSKU .padStart (19. `0').padstart(`sku');

B. productSKU = productSKU .padEnd (16. `0').padstart(`sku');

C. productSKU = productSKU .padEnd (16. `0').padstart(19, `sku');

D. productSKU = productSKU .padStart (16. `0').padstart(19, `sku');

Which statement accurately describes an aspect of promises?

A. Arguments for the callback function passed to .then() are optional.

B. In a.then()function, returning results is not necessary since callbacks will catch the result of a previous promise.

C. .then() cannot be added after a catch.

D. .then() manipulates and returns the original promise.

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?

A. Private packages can be scored, andscopes can be associated to a private registries.

B. Private registries are not supported by npm, but packages can be installed via URL.

C. Private packages are not supported, but they can use another package manager like yarn.

D. Private registries are not supported by npm, but packages can be installed via git.

A developer writes the code below to return a message to a user attempting to register a new username. If the username is available, a variable named nag is declared and assigned a value on line 03.

What is the value of msg when getAvailableabilityMessage ("newUserName") is executed and get Availability ("newUserName") returns true?

A. "msg is not defined"

B. "newUserName"

C. "User-name available"

D. undefined

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

A. Vue

B. Angular

C. Koa

D. Express