Which statement correctly declares a JavaScript function?

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

A). var x = 10;

B). let x = 10;

C). const x = 10;

D). variable x = 10;

Which statement correctly declares a JavaScript arrow function?

A). const add = (a, => a + b;

B). function add(a, { return a + b; }

C). const add = function(a, { return a + b; }

D). let add = function(a, { return a + b; };

What is the correct way to declare a JavaScript class?

A). class Rectangle {}

B). let Rectangle = {}

C). function Rectangle() {}

D). Rectangle {}

What does the '===' operator check in JavaScript?

A). Type and value equality

B). Type equality only

C). Value equality only

D). Reference equality

What is the purpose of the 'typeof' operator in JavaScript?

A). To check if a variable is defined

B). To check the data type of a variable

C). To assign a data type to a variable

D). To increment the value of a variable

What is the purpose of the 'this' keyword in JavaScript?

A). To refer to the current HTML element

B). To refer to the current JavaScript file

C). To refer to the current object

D). To refer to the current function

How do you concatenate strings in JavaScript?

A). Using the + operator

B). Using the - operator

C). Using the * operator

D). Using the / operator

How can you convert a string to a number in JavaScript?

A). parseInt('10')

B). parseFloat('10.5')

C). Number('10')

D). All of the above

How can you prevent a JavaScript function from executing immediately?

A). Using async/await

B). Using the defer attribute in HTML script tag

C). Wrapping the function in parentheses

D). Using the setTimeout function

How can you comment a single line of code in JavaScript?

A). // This is a comment

B). <!-- This is a comment -->

C). /* This is a comment */

D). ''' This is a comment '''