The 'extra' key value is a ______ value.

The 'extra' key value is a ______ value.

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

Answer: (B)

A null value is used to show that there is no value for that field. When the 'extra' key is assigned null, it signals that there’s intentionally no additional data to provide for this field. This is different from a string, number, or boolean, which would carry actual data (text, a number, or true/false). Using null makes the absence explicit, which is helpful for data schemas where the field exists but may not have content. If the key were simply missing, that would also mean no data, but having it set to null explicitly communicates the absence.

A null value is used to show that there is no value for that field. When the 'extra' key is assigned null, it signals that there’s intentionally no additional data to provide for this field. This is different from a string, number, or boolean, which would carry actual data (text, a number, or true/false). Using null makes the absence explicit, which is helpful for data schemas where the field exists but may not have content. If the key were simply missing, that would also mean no data, but having it set to null explicitly communicates the absence.