Control Flow and Functions: Interactive Learning Quizzes for Web Development

Question 1

Which JavaScript statement is used to conditionally execute code?

Accepted Answer

if

Answer

for

Answer

while

Answer

break

Question 2

Which JavaScript keyword is used to create a function?

Accepted Answer

function

Answer

var

Answer

let

Answer

const

Question 3

What is the result of the following JavaScript expression: 10 % 3?

Accepted Answer

1

Answer

0

Answer

3

Answer

10

Question 4

Which JavaScript operator is used to perform logical AND?

Accepted Answer

&&

Answer

||

Answer

!

Answer

?

Question 5

What is the primary purpose of the switch statement in JavaScript?

Accepted Answer

To execute specific code based on a given value or expression

Answer

To iterate over an array

Answer

To define a function

Answer

To control the flow of execution

Question 6

Which JavaScript keyword is used to immediately terminate the execution of a loop?

Accepted Answer

break

Answer

continue

Answer

return

Answer

throw

Question 7

What is the key difference between 'var' and 'let' variable declarations in JavaScript?

Accepted Answer

Variables declared with 'let' have block scope, while variables declared with 'var' have function scope

Answer

Variables declared with 'let' can be re-declared, while variables declared with 'var' cannot

Answer

Variables declared with 'var' are hoisted, while variables declared with 'let' are not

Answer

There is no significant difference between 'var' and 'let' variable declarations

Question 8

In JavaScript, which of the following is the correct syntax for an if-else statement?

Accepted Answer

if (condition) { statement } else { statement }

Answer

if (condition) { statement } otherwise { statement }

Answer

if (condition) { statement } then { statement }

Answer

if condition { statement } else condition { statement }

Question 9

Which code correctly prints the values from 0 to 4 to the console?

Accepted Answer

for (i = 0; i < 5; i++) { console.log(i); }

Answer

for (i = 0 to 5; i++) { console.log(i); }

Answer

for i in range(0, 5): { print(i); }

Answer

for (let i = 0; i < 5; i; i++) { console.log(i); }

Question 10

Which of the following is NOT a valid comparison operator in JavaScript?

Accepted Answer

=

Answer

==

Answer

!=

Answer

>=

Question 11

Which of the following is a valid way to invoke a function in JavaScript?

Accepted Answer

myFunction();

Answer

myFunction;

Answer

function myFunction();

Answer

myFunction = ();

Question 12

Consider the function: function sum(a, b) { return a + b; }. What is the result of calling sum(3, 4)?

Accepted Answer

7

Answer

34

Answer

undefined

Answer

Error

Question 13

Which of the following is NOT a valid data type in JavaScript?

Accepted Answer

Integer

Answer

String

Answer

Boolean

Answer

Array

Question 14

How do you determine the number of elements in an array in JavaScript?

Accepted Answer

array.length

Answer

array.size

Answer

len(array)

Answer

array[length]

Question 15

What is the primary purpose of the break statement in a loop?

Accepted Answer

To immediately terminate the loop

Answer

To skip the current iteration of the loop

Answer

To continue the loop from the next iteration

Answer

To pause the loop execution

Question 16

In an if-else structure, the purpose of the 'else' clause is to:

Accepted Answer

Run code if the 'if' condition evaluates to false

Answer

Run code if the 'if' condition evaluates to true

Answer

Terminate the if-else structure

Answer

Define a new variable within the structure

Question 17

In JavaScript, which operator represents logical AND operation?

Accepted Answer

&&

Answer

||

Answer

|

Answer

&

Question 18

In JavaScript, the method to convert a string to uppercase is:

Accepted Answer

toUpperCase()

Answer

toUpper()

Answer

upperCase()

Answer

toUpperString()

Question 19

What result will the following JavaScript code produce: console.log(typeof null);

Accepted Answer

object

Answer

null

Answer

undefined

Answer

string

Question 20

Which control flow statement is used to execute a block of code only if a specified condition is true?

Accepted Answer

if statement

Answer

while loop

Answer

for loop

Answer

switch statement

Question 21

What is the correct syntax to declare a function in JavaScript?

Accepted Answer

function functionName() {}

Answer

define functionName() {}

Answer

def functionName() {}

Answer

function() functionName {}

Question 22

What is the purpose of the 'return' statement in a function?

Accepted Answer

To end the function execution and return a value.

Answer

To terminate the program execution.

Answer

To pause the function execution.

Question 23

Which of the following is the correct syntax to invoke a function?

Accepted Answer

functionName();

Answer

execute functionName();

Answer

call functionName();

Question 24

What is the difference between a while loop and a for loop?

Accepted Answer

A while loop executes as long as the provided condition is true, whereas a for loop iterates over a defined range of values.

Answer

A while loop is more efficient than a for loop.

Question 25

What is the function of the 'break' statement within a loop?

Accepted Answer

To terminate the loop immediately and resume execution after the loop.

Answer

To increment the loop counter.

Answer

To evaluate the loop's condition.