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

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

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

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

A). Number

B). String

C). Object

D). Undefined

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

What is a primitive value in JavaScript?

A). A complex data structure

B). A basic data type

C). A function

D). An array

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 data type of the value undefined in JavaScript?

A). String

B). Object

C). Undefined

D). Number