What is the result of the expression 5 + '5' in JavaScript?
A). 10
B). '55'
C). '10'
D). Error
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
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
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 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
Which of the following is a primitive data type in JavaScript?
A). Array
B). Object
C). Function
D). String
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