The 'extra' key value is a _________ value.

The 'extra' key value is a _________ value.

• A. string
• B. array
• C. numeric
• D. boolean

Answer: (D)

A boolean value is used for flags that indicate a yes/no state. The term extra often implies a toggle: is the extra feature enabled or not? Booleans encode exactly that binary choice with true or false, which makes them the natural fit for such a setting. If it were a string, it would be text; if numeric, it would convey a quantity or code; if an array, it would list items. None of those capture a simple on/off condition as clearly as a boolean. So the extra key value is best represented as true or false.

A boolean value is used for flags that indicate a yes/no state. The term extra often implies a toggle: is the extra feature enabled or not? Booleans encode exactly that binary choice with true or false, which makes them the natural fit for such a setting. If it were a string, it would be text; if numeric, it would convey a quantity or code; if an array, it would list items. None of those capture a simple on/off condition as clearly as a boolean. So the extra key value is best represented as true or false.