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

What is the result of the following code: let x = 5; x = 'hello'; console.log(typeof x);?

A). number

B). string

C). undefined

D). object

What does the isNaN function do?

A). Checks if a value is not a number

B). Converts a value to a number

C). Checks if a value is a number

D). Converts a value to NaN

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

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

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

Given let a = '10'; let b = 20;, what is the result of a + b?

A). 30

B). 1020

C). 30

D). NaN

What is the result of typeof [] in JavaScript?

A). array

B). object

C). list

D). undefined