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

Which type conversion happens automatically in the expression 3 + '5'?

A). Number to String

B). String to Number

C). Boolean to String

D). Number to Boolean

What is the type of the value returned by parseFloat('3.14abc')?

A). number

B). string

C). NaN

D). undefined

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

A). number

B). boolean

C). string

D). object

What is the type of the value returned by JSON.parse('null')?

A). null

B). string

C). object

D). undefined

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 is the initial type of a variable declared with let a;?

A). null

B). number

C). undefined

D). object

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

A). number

B). string

C). undefined

D). object

Which of the following values is considered falsy in JavaScript?

A). 1

B). 0

C). 0

D). {}

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