Which of the following is a primitive data type in JavaScript?

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 data type of the value undefined in JavaScript?

A). String

B). Object

C). Undefined

D). Number

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

A). undefined

B). null

C). 0

D). Error

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

A). #

B). $

C). !

D). true/false

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

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

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

A). SyntaxError is thrown

B). ReferenceError is thrown

C). TypeError is thrown

D). Undefined

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