Which data type represents variables that have been explicitly set to have no value?
A). Number
B). Undefined
C). String
D). Null
Which primitive data type represents variables that are declared but not initialized?
A). Number
B). String
C). Undefined
D). Null
What does the expression typeof '123' return in JavaScript?
A). number
B). string
C). undefined
D). boolean
What does the expression typeof true return in JavaScript?
A). number
B). string
C). boolean
D). undefined
What does the expression typeof 42 return in JavaScript?
A). number
B). string
C). undefined
D). boolean
How is the Symbol data type different from other primitive data types in JavaScript?
A). Symbols can be used as object keys
B). Symbols can be compared directly
C). Symbols can be used in mathematical operations
D). Symbols can be concatenated with strings
Which of the following statements accurately describes the Boolean data type in JavaScript?
A). It represents textual data
B). It represents numeric data
C). It represents logical values
D). It represents an absence of value
How is the Undefined data type different from the Null data type in JavaScript?
A). Undefined represents an intentional absence of value
B). Null represents variables not initialized
C). Undefined is used for object keys
D). Null is used for mathematical operations
What does the Boolean data type represent in JavaScript?
A). Textual data
B). Numeric data
C). Logical values
D). Absence of value
What is the result of the expression typeof 'Hello' in JavaScript?
A). number
B). string
C). undefined
D). boolean