Which of these is a complex or reference data type in JavaScript?

What will let x = '10'; let y = x - 5; console.log(y); output in JavaScript?

A). '5'

B). 5

C). '10'

D). 10

What does NaN represent in JavaScript?

A). Not a Number

B). Infinity

C). Positive Infinity

D). Negative Infinity

What is the data type of the value 42 in JavaScript?

A). String

B). Boolean

C). Number

D). Null

What is the outcome of typeof [1, 2, 3] in JavaScript?

A). String

B). Number

C). Array

D). Object

Which data type represents an intentional absence of any value in JavaScript?

A). Null

B). Undefined

C). String

D). Number

What is the data type of the value 'null' (with quotes) in JavaScript?

A). String

B). Number

C). Null

D). Undefined

What will the following code snippet output: let a = 10; a += '5'; console.log(a); in JavaScript?

A). '105'

B). 105

C). 15

D). '15'

What is the data type of the value true in JavaScript?

A). Number

B). String

C). Boolean

D). Undefined

What is the data type of the value undefined in JavaScript?

A). Number

B). Boolean

C). String

D). Undefined

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

A). Array

B). Symbol

C). Map

D). Tuple