This code uses a for loop to create circles out of randomly colored rings. Every frame, a random size and location is generated, and then the for loop goes from size to 0, decreasing by a random value between 2 and 10. In other words, the loop starts at the outer-most ring, then decreases in size randomly until it’s too small to see. This causes the circles to be drawn with randomly colored, randomly sized rings.
This is a companion discussion topic for the original entry at https://happycoding.io/examples/processing/for-loops/random-circles