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

What is the result of the expression true + false in JavaScript?

A). true

B). false

C). 1

D). 0

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

A). String

B). Object

C). Undefined

D). Number

Which of the following statements about primitive values in JavaScript is true?

A). They are mutable

B). They are passed by reference

C). They are stored on the heap

D). They are immutable

Which primitive value represents absence of value or no value assigned?

A). undefined

B). null

C). 0

D). 'undefined'

What is the result of the expression undefined + null in JavaScript?

A). undefined

B). null

C). 0

D). Error

Which of the following is a valid JavaScript symbol?

A). symbol

B). &symbol

C). #symbol

D). Symbol('description')

What is the result of the expression 5 + '5' in JavaScript?

A). 10

B). '55'

C). '10'

D). Error

What is the result of the expression true == 1 in JavaScript?

A). true

B). false

C). Error

D). 1

What does the Symbol data type represent in JavaScript?

A). A unique identifier

B). A number

C). A boolean value

D). An object

Which of the following statements is true about JavaScript's null value?

A). It represents an empty string

B). It represents a non-existent value

C). It represents a boolean value

D). It represents a number