Which primitive data type stores decimal numbers with the most precision among the common types?

Which primitive data type stores decimal numbers with the most precision among the common types?

• A. Float
• B. Double
• C. Long
• D. Decimal

Answer: (B)

Precision is about how many digits a type can represent reliably. The double type uses 64 bits for its floating-point representation, giving roughly 15–16 significant decimal digits of precision, which is more than the float’s about 7 digits. So for decimal numbers where you want the most accuracy among common primitive types, double is the best choice. The long type is integer and cannot represent fractions. The decimal type can be very precise in some languages, but among the standard primitive types used for general arithmetic, the 64-bit floating-point type provides the greatest precision.

Precision is about how many digits a type can represent reliably. The double type uses 64 bits for its floating-point representation, giving roughly 15–16 significant decimal digits of precision, which is more than the float’s about 7 digits. So for decimal numbers where you want the most accuracy among common primitive types, double is the best choice. The long type is integer and cannot represent fractions. The decimal type can be very precise in some languages, but among the standard primitive types used for general arithmetic, the 64-bit floating-point type provides the greatest precision.