What does the isNaN function do?

Given the code: let y = 10; y = true;, what is the type of y after execution?

A). number

B). boolean

C). string

D). object

In JavaScript, what will be the type of a variable x after x = 5 + true;?

A). number

B). string

C). boolean

D). undefined

What will be the result of the following code: let z = '123'; z = Number(z); console.log(typeof z);?

A). string

B). number

C). undefined

D). boolean

What will typeof null return in JavaScript?

A). null

B). undefined

C). object

D). number

How can you check if a variable is an array in JavaScript?

A). typeof variable === 'array'

B). Array.isArray(variable)

C). variable instanceof array

D). variable.constructor === array

What happens when you add a number and a string in JavaScript?

A). An error is thrown

B). The number is converted to a string

C). The string is converted to a number

D). Both are converted to boolean

What does the parseInt function do in JavaScript?

A). Converts a number to a string

B). Converts a string to an integer

C). Converts a boolean to a number

D). Converts an array to a number

What will be the result of typeof function() {} in JavaScript?

A). function

B). object

C). undefined

D). method

Which operator is used to determine the type of a variable in JavaScript?

A). typeof

B). instanceof

C). type

D). isType

What is the result of typeof [] in JavaScript?

A). array

B). object

C). list

D). undefined