Delphi: Round a number to thousands place (12345678 to 12345000)

This cannot be done with the typical Delphi round() function like you can do it when rounding in PHP using a negative precision.

Just try the following code instead:

var
  k: integer;
begin
  k := 123456;
  k := round(k/1000) * 1000;
  showmessage(inntostr(k));  // 123000

If you always want to round down like in your example, you can use the function floor or trunc instead of round:

k := 12345678;
k := floor(k/1000) * 1000;  // k = 12345000

Because you brought me to that idea, I have just written a small function to round a number to any decimal place in Delphi. In this function you can use positive or negative values as a second parameter in order to round to a position after or before the decimal point.
2014-02-21 at 01:42

Perhaps, also the build in function RoundTo from the unit Math can help you:

x:=RoundTo(12345, 3);  //12000

Or with setting the Round Mode:

SetRoundMode(rmTruncate);
x:=RoundTo(12345678, 3);  //12345000

SetRoundMode accepts the following parameters:

To prevent the function from rounding up, you can just use the rmTruncate mode.
2014-02-21 at 02:58