Which of the following is a valid JavaScript symbol?
A). symbol
B). &symbol
C). #symbol
D). Symbol('description')
What is the default value of a variable in JavaScript if it is not initialized?
A). null
B). undefined
C). 0
D). 'undefined'
What is the data type of the value NaN in JavaScript?
A). Number
B). String
C). Object
D). Undefined
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 result of the expression true + false in JavaScript?
A). true
B). false
C). 1
D). 0
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 of the following is not a primitive value in JavaScript?
A). Number
B). Boolean
C). Object
D). String
What is the result of the expression true == 1 in JavaScript?
A). true
B). false
C). Error
D). 1
Which symbol is used to represent a boolean value in JavaScript?
A). #
B). $
C). !
D). true/false
What does the Symbol data type represent in JavaScript?
A). A unique identifier
B). A number
C). A boolean value
D). An object