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

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

A). String

B). Number

C). Array

D). Object

What is the result of 0 / 0 in JavaScript?

A). Infinity

B). 0

C). NaN

D). 1

What is the outcome of typeof undefined in JavaScript?

A). String

B). Undefined

C). Null

D). Number

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

A). String

B). Number

C). Null

D). Undefined

What does NaN represent in JavaScript?

A). Not a Number

B). Infinity

C). Positive Infinity

D). Negative Infinity

Which data type represents unique and immutable values in JavaScript introduced in ES6?

A). Symbol

B). Object

C). Array

D). Function

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

A). '5'

B). 5

C). '10'

D). 10

Which of the following is a primitive data type in JavaScript?

A). Object

B). Array

C). Function

D). Boolean

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

A). Number

B). String

C). Boolean

D). Undefined