Null error

Comments

• gordk St.Catherines On. Canada.

  June 2004 edited 7:46AM

  Yes I would expect that error you have hard coded a bad index value to occur
  the index values you have given MyArr[] when you added data to the array elements have no relation to either rtid or rt the value you are using as an index when trying to retreive the value stored in the array elements.
  begin
  rtID := [rt];
  
  MyArr[1] := 'A';
  MyArr[2] := 'B';
  MyArr[3] := 'C';
  
  memo10.lines.clear;
  memo10.lines.add(MyArr[rtID]);
  end
  
  In other words the only valid data in MyArr lies in elements with an index value of 1 to 3, any other value in rtid will produce the error because the array element index value is non existent.
  So it is up to the programmer to supply valid index values when loading data into and retrieving data from the array.
  for a good example of how to use the array see the
  fr\demo\reports demo project and look at the report titled group totals in header.
  regards
• khh

  June 2004 edited 7:46AM

  I tried this
  
  if [rt]=nil then
  rtID := 0
  else
  rtID := [rt];
  
  MyArr[0] := '0';
  MyArr[1] := 'A';
  MyArr[2] := 'B';
  MyArr[3] := 'C';
  
  memo10.lines.clear;
  memo10.lines.add(MyArr[rtID]);
  
  
  I get 'Undefined symbol ''NIL'''
  
  ?!!!!!!!!!!!!!!!!
• gordk St.Catherines On. Canada.

  June 2004 edited 7:46AM

  nil is not usable in the script
  again
  look at the demo as suggested and you will see the correct way to use an array and its index.
  regards