What is the best way to fill a 2D array?-CodePudding

I am trying to fill an array using data from a database (Access), but when I run this code:

with dmSUPREMEDATA do
begin
  iNumberofRecords := ADOComplete.RecordCount;
  ADOComplete.First;
  SetLength(ArrSummary, iNumberofRecords, 3);
  for i := 0 to iNumberofRecords do
  begin
    ArrSummary[i, 0] := ADOComplete['Names'];
    ArrSummary[i, 1] := ADOComplete['Surnames'];
    ArrSummary[i, 2] := ADOComplete['Average'];
    ADOComplete.Next;
  end;
end;

This is the error that pops up:

Is there a better way to fill the array? This is coded with delphi

CodePudding user response：

Your loop is going out out bounds of the array.

The 1st dimension of the array has iNumberofRecords number of elements, so it has valid indexes 0..iNumberofRecords-1. The indexes that a for loop uses are inclusive, so you are looping through indexes 0..iNumberofRecords, which means the final iteration of the loop is accessing an invalid index.

You need to subtract -1 from the loop counter, eg:

for i := 0 to iNumberofRecords-1 do

or:

for i := 0 to Pred(iNumberofRecords) do

CodePudding user response：

You can try create two for loops. Like a detail and subdetail, being one for the first array and other for the second.


var arr2d := array of array of string;

SetLength(arr2d, 5, 5);

for var i := 0 to Length(arr2d) - 1 do
begin
  for var j := 0 to Length(arr2d) - 1 do
    arr2d[i][j] := 'Text ['   i.ToString   ']['   j.toString   ']';
end