Question

i’ve came across a simple loop which seems to go into the loop regardless of a parameter i query in order to determine whether the loop should process. Below is the loop;

  if (result[4] == 0x01 || result[5] == 0x01 || result[6] == 0x01 || result[7] == 0x01 || result[8] == 0x01 || result[9] == 0x01 & deviceState == false)
                {

                        deviceState = true;
                        mainUI.setAlarmColour(result, device);

                }

note: i’ve tried “&” and “&&” for the final parameter, but both make no difference.

With this loop, even if deviceState is set to true, it proceeds to enter the loop. However, if i use the following loop it stops this issue:

  if (result[4] == 0x01 || result[5] == 0x01 || result[6] == 0x01 || result[7] == 0x01 || result[8] == 0x01 || result[9] == 0x01)
                {
                    if (deviceState == false)
                    {
                        deviceState = true;
                        mainUI.setAlarmColour(result, device);
                    }
                }

This second loops solves the problem and it no longer proceeds into the loop, meaning my function isn’t called.

am I missing something fundamental here? I’ve tried messageBoxes to verify that it’s false and they return the way I’d expect, yet it still enters the first loop.

Answer 1

First it’s && like you already tried (& is a bitwise operator), but you should group your ORs together and have the final AND standalone, like so:

if (
    (result[4] == 0x01 || result[5] == 0x01 || result[6] == 0x01 ||
     result[7] == 0x01 || result[8] == 0x01 || result[9] == 0x01)
   && deviceState == false)
{
    deviceState = true;
    mainUI.setAlarmColour(result, device);
}

Note that you can also change deviceState == false to simply !deviceState (if it’s a non-nullable bool). ! flips false to true for the comparison so you’re essentially saying the exact same thing, albeit shorter.

(Please ignore ugly formatting, just trying to show it clearer)