如何将大数字格式化为字符串以在Delphi中显示

Question

I have a double type big number, say 1111111111111110000000000000.000. How to format it to string for display in Delphi?

I've tried FloatToStr and FormatFloat , but I receive the Scientific Notation which is not what I want.

Answer 1

Using the System.Str conversion works:

var
  d: Double;
  s: String;
begin
  d := 1111111111111110000000000000.000;
  Str(d:0:3,s);
  WriteLn(s);
end;

Outputs: 1111111111111109950000000000.000

Note: double precision has not the precision to exactly hold the digits you are trying to input.

Normally in that case you would not show all digits, since this can give the impression that they all are accurate. This is why the scientific notation is prefered.