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

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

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

A). true

B). false

C). Error

D). 1

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

A). String

B). Object

C). Undefined

D). Number

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

A). Number

B). Boolean

C). Object

D). String

Which of the following is a valid JavaScript symbol?

A). symbol

B). &symbol

C). #symbol

D). Symbol('description')

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 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

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

A). undefined

B). null

C). 0

D). 'undefined'

What does the Symbol data type represent in JavaScript?

A). A unique identifier

B). A number

C). A boolean value

D). An object