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 way to represent the value null in JavaScript?
A). undefined
B). NULL
C). null
D). None of the above
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 is not a primitive value in JavaScript?
A). Number
B). Boolean
C). Object
D). String
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
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 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
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