Mega Code Archive

Double - a floating point type supporting about 15 digits of precision

type Double; Description The Double type is the general purpose floating point type in Delphi. It strikes the balance between capacity/precision versus storage/performance. It supports approximately 15 digits of precision in a range from 2.23 x 10-308 to 1.79 x 10308. Notes The Single type is smaller and faster, but with reduced capacity and precision. The Extended type has the highest capacity and precision, but biggest storage and worst performance. A Double set to its highest value is treated as Infinity. Related commands Currency A floating point type with 4 decimals used for financial values Extended The floating point type with the highest capacity and precision Single The smallest capacity and precision floating point type Example code : Showing the precision and capacity of Double values var account1, account2, account3, account4 : Double; begin account1 := 0.1234567890123456789; // 20 decimal places account2 := 1.234567890123456789E308; // Highest exponent value account3 := account1 + account2; account4 := 9.9E308; // Treated as infinite ShowMessage('Account1 = '+FloatToStr(account1)); ShowMessage('Account2 = '+FloatToStr(account2)); ShowMessage('Account3 = '+FloatToStr(account3)); ShowMessage('Account4 = '+FloatToStr(account4)); end; Show full unit code Account1 = 0.123456789012346 Account2 = 1.23456789012346E308 Account3 = 1.23456789012346E308 Account4 = INF