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

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

A). true

B). false

C). 1

D). 0

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 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 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 happens when you add two numbers using the + operator in JavaScript?

A). The numbers are concatenated

B). The numbers are multiplied

C). The numbers are added

D). An error occurs

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

A). undefined

B). null

C). 0

D). 'undefined'

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 symbol is used to represent a boolean value in JavaScript?

A). #

B). $

C). !

D). true/false

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

A). Number

B). String

C). Object

D). Undefined

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

A). null

B). undefined

C). 0

D). 'undefined'