Which data type represents a block of reusable code in JavaScript?

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

A). Null

B). Undefined

C). String

D). Number

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

A). String

B). Number

C). Array

D). Object

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

A). '5'

B). 5

C). '10'

D). 10

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

A). Symbol

B). Object

C). Array

D). Function

Which operator checks if an object is an instance of a specific object type in JavaScript?

A). instanceof

B). typeof

C). isInstanceof

D). isTypeOf

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

A). Object

B). Array

C). Function

D). Boolean

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'

Which data type represents positive infinity in JavaScript?

A). Infinity

B). Number

C). NaN

D). Null

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

A). Number

B). String

C). Boolean

D). Undefined

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

A). Array

B). Symbol

C). Map

D). Tuple