Code

size(400,100);
background(255);
smooth();
noStroke();

int spacing = 30;

for (int i=1; i<=10; i=i+1){
  if (i%3==1){
    fill (255,0,0);
  }else {
    fill (0);
  }ellipse (50+ i*spacing, 50, 25,25);
}

0209 - Conditionals within a for{} loop III: if{} and the % operator

Statement:For this assignment, you are limited to a single for{} loop and a single if{} structure.
Set up the placement of ten circles using a single for{} loop, as you have done in the previous two assignments. (In this particular exercise, it may be easiest if the counting variable of your for{} loop counts from 0 to 9).

The modulus operator (%) is useful for determining whether a number is an round multiple of some other number. For this assignment, use the modulus operator and an if{} structure to color every third circle red. Circles representing counts which are not a multiple of 3, should be filled black.

Here is what your result should look like:

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