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