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JavaScript Basics Quiz

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Question 1/15

What method is used to add new elements to the end of an array?

Select your answer

append()

insert()

add()

push()

Question 2/15

What will the following expression return: Boolean(0);

Boolean(0);

Select your answer

true

null

undefined

false

Question 3/15

Which method can be used to convert a JSON string into a JavaScript object?

Select your answer

JSON.stringify()

JSON.convert()

JSON.toString()

JSON.parse()

Question 4/15

What will the value of "x" be after the code is run?

let x = 5;
x = x * 2;

Select your answer

undefined

Question 5/15

Which company developed JavaScript?

Select your answer

Microsoft

Netscape

Sun Microsystems

Apple

Question 6/15

Which of the following data types exists in JavaScript?

Select your answer

Character

Hexadecimal

Tuple

String

Question 7/15

How do you round 7.25 to the nearest integer in JavaScript?

Math.round(7.25);

Select your answer

Math.rnd(7.25)

rnd(7.25)

round(7.25)

Math.round(7.25)

Question 8/15

Which operator is used to assign a value to a variable?

Select your answer

===

Question 9/15

What will the following code output?

var fruits = ['Apple', 'Banana', 'Mango'];
console.log(fruits[1]);

Select your answer

Mango

Banana

fruits

Apple

Question 10/15

Which one of these is an Arrow Function syntax?

Select your answer

(x, y) => x + y

function(x, y){ return x + y; }

func (x, y) => x + y

function => (x, y){ x + y }

Question 11/15

How do you find the number with the highest value of x and y?

Math.max(x, y);

Select your answer

ceil(x, y)

top(x, y)

Math.max(x, y)

Math.ceil(x, y)

Question 12/15

What is the correct way to declare a variable in JavaScript?

Select your answer

v myVariable;

variable myVariable;

declare myVariable;

var myVariable;

Question 13/15

What is a typical use case for the "isNaN()" function?

Select your answer

To find the maximum number.

To check if a value is not a number.

To convert a value to a string.

To append a string to a number.

Question 14/15

What is the output when you execute the following code?

console.log(typeof 42);

Select your answer

number

integer

object

string

Question 15/15

How do you write an "if" statement in JavaScript to execute some code if "i" is equal to 5?

if (i === 5) {
    // code to execute
}

Select your answer

if (i === 5)

if i == 5 then

if i = 5 then

if i = 5

Your Results

You did not answer any questions correctly.

Your Answers

Question 1/15

😊 Your answer was correct 🙁 Your answer was incorrect

What method is used to add new elements to the end of an array?

Available answers

append()

insert()

add()

push()

The

push()

method adds one or more elements to the end of an array.

Question 2/15

😊 Your answer was correct 🙁 Your answer was incorrect

What will the following expression return: Boolean(0);

Boolean(0);

Available answers

true

null

undefined

false

The expression

Boolean(0)

returns

false

because

is considered a "falsy" value in JavaScript.

Question 3/15

😊 Your answer was correct 🙁 Your answer was incorrect

Which method can be used to convert a JSON string into a JavaScript object?

Available answers

JSON.stringify()

JSON.convert()

JSON.toString()

JSON.parse()

The

JSON.parse()

method is used to convert a JSON string into a JavaScript object.

Question 4/15

😊 Your answer was correct 🙁 Your answer was incorrect

What will the value of "x" be after the code is run?

let x = 5;
x = x * 2;

Available answers

undefined

The operation

x = x * 2

assigns the result of

5 * 2

, which is

Question 5/15

😊 Your answer was correct 🙁 Your answer was incorrect

Which company developed JavaScript?

Available answers

Microsoft

Netscape

Sun Microsystems

Apple

JavaScript was developed by Netscape as a client-side scripting language.

Question 6/15

😊 Your answer was correct 🙁 Your answer was incorrect

Which of the following data types exists in JavaScript?

Available answers

Character

Hexadecimal

Tuple

String

JavaScript supports data types such as

String, Number, Boolean, Object

, but not specific types like

Character

Tuple

Question 7/15

😊 Your answer was correct 🙁 Your answer was incorrect

How do you round 7.25 to the nearest integer in JavaScript?

Math.round(7.25);

Available answers

Math.rnd(7.25)

rnd(7.25)

round(7.25)

Math.round(7.25)

To round a number in JavaScript, use

Math.round()

Question 8/15

😊 Your answer was correct 🙁 Your answer was incorrect

Which operator is used to assign a value to a variable?

Available answers

===

The assignment operator in JavaScript is

, used to assign values to variables.

Question 9/15

😊 Your answer was correct 🙁 Your answer was incorrect

What will the following code output?

var fruits = ['Apple', 'Banana', 'Mango'];
console.log(fruits[1]);

Available answers

Mango

Banana

fruits

Apple

Arrays in JavaScript are zero-indexed, so

fruits[1]

contains

'Banana'

Question 10/15

😊 Your answer was correct 🙁 Your answer was incorrect

Which one of these is an Arrow Function syntax?

Available answers

(x, y) => x + y

function(x, y){ return x + y; }

func (x, y) => x + y

function => (x, y){ x + y }

An Arrow Function does not use the

function

keyword and looks like

(x, y) => x + y

Question 11/15

😊 Your answer was correct 🙁 Your answer was incorrect

How do you find the number with the highest value of x and y?

Math.max(x, y);

Available answers

ceil(x, y)

top(x, y)

Math.max(x, y)

Math.ceil(x, y)

The function

Math.max()

is used to find the highest value among its parameters.

Question 12/15

😊 Your answer was correct 🙁 Your answer was incorrect

What is the correct way to declare a variable in JavaScript?

Available answers

v myVariable;

variable myVariable;

declare myVariable;

var myVariable;

In JavaScript, you declare a variable using the

var

let

, or

const

keyword, such as

var myVariable;

Question 13/15

😊 Your answer was correct 🙁 Your answer was incorrect

What is a typical use case for the "isNaN()" function?

Available answers

To find the maximum number.

To check if a value is not a number.

To convert a value to a string.

To append a string to a number.

The

isNaN()

function checks if a value is NaN (Not-a-Number).

Question 14/15

😊 Your answer was correct 🙁 Your answer was incorrect

What is the output when you execute the following code?

console.log(typeof 42);

Available answers

number

integer

object

string

The

typeof

operator returns

'number'

for numerical literals like

Question 15/15

😊 Your answer was correct 🙁 Your answer was incorrect

How do you write an "if" statement in JavaScript to execute some code if "i" is equal to 5?

if (i === 5) {
    // code to execute
}

Available answers

if (i === 5)

if i == 5 then

if i = 5 then

if i = 5

The syntax for an "if" statement in JavaScript to check for equality is:

if (i === 5) { /* code */ }