Round / Truncate floating point numbers to N decimal places in Inno Setup Pascal Script

If rounding is acceptable, an easy solution is using the Format function:

var
  Height, Width: Integer;
  DivisionOfHeightWidthF: Single;
begin
  ...
  DivisionOfHeightWidthF := Single(Width) / Height;
  Log(Format('The Division Of Height and Width: %.2f', [DivisionOfHeightWidthF]));
end;

For details on the format string, see Delphi documentation for the Format function.

Note that the Format uses a locale-specific number format (decimal separator particularly).

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If you really need truncating, you need to implement it yourself like:

var
  Height, Width: Integer;
  DivisionOfHeightWidthF: Single;
  S: string;
  P: Integer;
begin
  ...
  DivisionOfHeightWidthF := Single(Width) / Height;
  S := FloatToStr(DivisionOfHeightWidthF);
  P := Pos('.', S);
  if P < Length(S) - 2 then
  begin
    SetLength(S, P + 2);
  end;
  Log(S);
end;

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The above works in Unicode Inno Setup only as in Ansi version the FloatToStr uses locale-specific decimal separator, i.e. not always the .. In current Inno Setup 6, the Unicode version is the only version.