Question

I have variable:

data: TIdBytes;

it contains some amount of data.

How to read first byte of “data”, and delete the first byte from “data” ?

And yes, I will do it again and again. Until “data” will be empty.

I will use the copied byte with “IF”

if $0F = Copiedbyte then
 do_somthing;

maybe deleting is not so necessary, I just can copy next byte..

I don’t need loop, i just need to copy one byte the do something with it, for example save for later use.

Answer 1

You don’t need to delete anything and it seems wasteful to do so. It would make your code messier and cost CPU time.

Just iterate over the array of bytes:

var
  b: byte;
....
for b in data do
  dosomething(b);

If you don’t want to do this in a loop, keep track of the index of the next byte to be processed. Every time you process a byte, increment the index.

function GetNext(
  const data: TIdBytes;
  var Index: Integer; 
  var b: Byte
): Boolean;
begin
  Result := Index<=high(data);
  if Result then
  begin
    b := data[Index];
    inc(Index);
  end;
end;

Initialise an index variable to 0 and keep calling this function, extracting one byte at a time, until it returns False.