What happens when you try to access a variable that has not been declared in JavaScript?

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

A). true

B). false

C). Error

D). 1

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 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 undefined in JavaScript?

A). String

B). Object

C). Undefined

D). Number

Which symbol is used to represent a boolean value in JavaScript?

A). #

B). $

C). !

D). true/false

What is a primitive value in JavaScript?

A). A complex data structure

B). A basic data type

C). A function

D). An array

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

A). 10

B). '55'

C). '10'

D). Error

What does the Symbol data type represent in JavaScript?

A). A unique identifier

B). A number

C). A boolean value

D). An object

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 NaN in JavaScript?

A). Number

B). String

C). Object

D). Undefined