What is the result of the expression 5 + '5' in JavaScript?
A). 10
B). '55'
C). '10'
D). Error
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 primitive data type in JavaScript?
A). Array
B). Object
C). Function
D). String
What does the Symbol data type represent in JavaScript?
A). A unique identifier
B). A number
C). A boolean value
D). An object
Which symbol is used to represent a boolean value in JavaScript?
A). #
B). $
C). !
D). true/false
What is the result of the expression undefined + null in JavaScript?
A). undefined
B). null
C). 0
D). Error
Which primitive value represents absence of value or no value assigned?
A). undefined
B). null
C). 0
D). 'undefined'
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 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