FloatToStr

function FloatToStr(Value Extended):string;

The FloatToStr function converts a floating point number Value into a displayable string. The value is displayed to 15 digits of precision. The Value type may be any of the floating point types.

Example:

var
  LongNumberValue, ShortNumberValue : float;

begin
  LongNumberValue := 1234567890.123456789;
  ShortNumberValue := 123.12;

  ShowMessage('LongNumberValue = '+FloatToStr(LongNumberValue));
  ShowMessage('ShortNumberValue = '+FloatToStr(ShortNumberValue));
end;

Output:

LongNumberValue = 1234567890,123456789
ShortNumberValue = 123,12