Why doesn't FOR-EACH give every output a different VALUE from ARRAY?

Processing Beginners
1

I made an array that I output in a loop. But every item I assign the array it keep giving the same value while I’ve put 4 values into the array. I’ve tried everything but it keeps giving the same value (330). I have also made use of a for loop but it gives the same results. Thank you.

  int[] sx = {330,390,335,345};
  
  for (int i : sx){
    copy(video, i, 170, 40, 40, 0, 0, video.width/4, video.height/4);
    
    copy(video, i, 170, 40, 40, 150, 150, video.width/4, video.height/4); 
    
    copy(video, i, 205, 40, 40, 300, 300, video.width/4, video.height/4);
    
    copy(video, i, 230, 60, 40, 400, 150, video.width/4, video.height/4);
    print(i);
  }

image
When I used print to see the output of the value it always starts with 330, is that the problem?

2

It is not clear what you are trying to do and your explanation as to the problem doesn’t help.

If you try

int[] sx = {330, 390, 335, 345};

for (int i : sx) {
  println(i);
}

you get the following output

330
390
335
345

which is exactly what you would expect.

So in your code you have 4 copy statements which are executed for each integer in the array. If we expand your code to remove the loop and shaow what is actually being executed we get

int i;

i = 330;
copy(video, i, 170, 40, 40, 0, 0, video.width/4, video.height/4);
copy(video, i, 170, 40, 40, 150, 150, video.width/4, video.height/4); 
copy(video, i, 205, 40, 40, 300, 300, video.width/4, video.height/4);
copy(video, i, 230, 60, 40, 400, 150, video.width/4, video.height/4);
print(i);

i = 390;
copy(video, i, 170, 40, 40, 0, 0, video.width/4, video.height/4);
copy(video, i, 170, 40, 40, 150, 150, video.width/4, video.height/4); 
copy(video, i, 205, 40, 40, 300, 300, video.width/4, video.height/4);
copy(video, i, 230, 60, 40, 400, 150, video.width/4, video.height/4);
print(i);

i = 335;
copy(video, i, 170, 40, 40, 0, 0, video.width/4, video.height/4);
copy(video, i, 170, 40, 40, 150, 150, video.width/4, video.height/4); 
copy(video, i, 205, 40, 40, 300, 300, video.width/4, video.height/4);
copy(video, i, 230, 60, 40, 400, 150, video.width/4, video.height/4);
print(i);

i = 345;
copy(video, i, 170, 40, 40, 0, 0, video.width/4, video.height/4);
copy(video, i, 170, 40, 40, 150, 150, video.width/4, video.height/4); 
copy(video, i, 205, 40, 40, 300, 300, video.width/4, video.height/4);
copy(video, i, 230, 60, 40, 400, 150, video.width/4, video.height/4);
print(i);

the copy function is executed 16 times.

3 Likes
3

One remark

Processing doesn’t update the screen throughout

So when you expect to see the changes that happen inside the for loop you won’t see it.

Is this your issue?

1 Like