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

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

A). String

B). Object

C). Undefined

D). Number

What is the default value of a variable in JavaScript if it is not initialized?

A). null

B). undefined

C). 0

D). 'undefined'

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 true == 1 in JavaScript?

A). true

B). false

C). Error

D). 1

Which of the following is a valid way to represent the value null in JavaScript?

A). undefined

B). NULL

C). null

D). None of the above

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

A). They have methods and properties

B). They can be used as keys in objects

C). They are instances of Object

D). They are passed by value

Which of the following is not a primitive value in JavaScript?

A). Number

B). Boolean

C). Object

D). String

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

A). undefined

B). null

C). 0

D). Error

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

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

A). Number

B). String

C). Object

D). Undefined