error whith option Verify method calls

[Hansvb]

When the option "Verify method calls" is checked  in de debugging options then i get an error on the next code:

Code: [Select]


var
arBestanden : array[1..250] of string;
i : Integer;
begin
  if arteller > 0 then
    begin
      for i := arteller downto 0 do
        begin
          deletefile(arBestanden[i]);
          arteller := arteller -1;
        end;
    end; 
end;
 

the error is a range check error on the line:

Code: [Select]

deletefile(arBestanden[i]);

[bylaardt]

arBestanden[0] ??
your array begins from 1 [1..250]

change your "downto 0" to "downto 1"  or fix your array [0..250]

[molly]

If the array indexes are causing you headaches, you might want to consider using the constructs low and high.

for i := arteller downto low(arBestanden) do

or

For i := low(arBestanden) to High(arbestanden)

Because you use a separate index, something like thing might be helpful as well:

Code: [Select]

Type
  arBestandenRange = 1..250;
var
  arTeller: arBestandenRange;
  arBestanden : array[arBestandenRange] of string;
  i : arBestandenRange;
begin
  if arteller >= low(arBestanden) then
  begin
    for i := arteller downto low(arBestanden) do
      begin
        deletefile(arBestanden[i]);
        arteller := arteller -1;
      end;
  end; 
end;

Or what would be my favourite:

Code: [Select]

Type
  arBestandenRange = 1..250;
var
  arTeller: arBestandenRange;
  arBestanden : array[arBestandenRange] of string;
begin
  while arTeller > low(arBestanden) do
  begin
    dec(arteller);
    deletefile(arBestanden[arTeller]);
  end;
end;

The range takes the headaches away because when you "out of range" the compiler will tell so, as well as runtime (when enabled).

[Hansvb]

My array starts with 1 and use downto 0. Stupid mistake.