&& VS || in While Loops?

Projects Programming
1

Hi there,
I feel really dumb asking this, I have about 10 experience in programming/scripting but I am only about a year in with Arduino.

Ok here goes:

I have a while loop that I want to continue until two conditions are met. Here is an example:

int x;
int y;
int xGoal;
int yGoal;
boolean dataComm;
setup(){
     Serial.begin(57600);
     x=0;
     y=0;
     dataComm=false;
}

loop(){
getSerialFromData();//gets the values for xGoal and yGoal
startCounting();

}

startCounting(){

while(dataComm==true){
   while((x!=xGoal)&&(y!=yGoal)){     
       
      if(x!=xGoal){        
       getSerialFromData();  //allows me to interrupt the counting and give it a new goal

      if(xDiff<0){
         x--;
       }
       else{
         x++;
       }
      }

      if(y!=yGoal){        
       getSerialFromData();
      if(yDiff<0){
         y--;
       }
       else{
         y++;
       }
   dataComm=false;
}

   getSerialFromData(){

     //read data from serial to populate xGoal and yGoal;
     
     xDiff=xGoal-x;
     yDiff=yGoal-y;
     dataComm=true;
}
}

Now, the above while loop will stop if either x==xGoal or y==yGoal but I don't want it to do that. I want it to stop when x==xGoal AND y==yGoal.

From all of my experience with C, C++, and C# && should be a logical AND, and this loop should keep going until both conditions are met.

However, It only works if I change

while((x!=xGoal) && (y!=yGoal))

to

while((x!=xGoal) || (y!=yGoal))

and I have no clue why. Can anyone explain what is going on?

I found the answer after I happened to come across a thread where someone was trying to satisfy two conditions in a while loop and I noticed that he used the double pipe and no one corrected him. Can anyone tell me why this is true?

Disclaimer: This is kind of pseudo code. There is a bunch more going on and I tried to include just the part confuses me. This actually moves some motors and listens to some sensors and gives me output.

Thank you,
Rob

2 
while((x!=xGoal) && (y!=yGoal))

If either goal is true, the while terminates.

You are testing xGoal then you are testing xGoal and then yGoal. Gets a bit difficult to follow.
Do you even need the while()?

3

while(!(x==xGoal && y==yGoal))

-jim lee

4

However, It only works if I change

while((x!=xGoal) && (y!=yGoal))

to

while((x!=xGoal) || (y!=yGoal))

Yes of course ! If you want the loop to break if botj

(x==xGoal)
(y==yGoal)

both are met. So that means i want the loop to continue if either of the original conditions are true, hence the 'or' ( || )

5

I have about 10 experience in programming/scripting

And you never encountered De Morgan's laws? Or even figured them out for yourself?