2D Array Help needed

Hi, I am hoping someone can help me again with my Processing assignment. This is a red and black checker board. The question is “add one line of code that will create a circle using the ellipse function and place it on the black square as shown by the illustration.”

Here is what I have so far. The last line is the one that I can’t figure out. Thanks in advance for any help.

int squareSize = 50; // Dimensions ask for 40x40 
int cols, rows;

void setup() {

  size(500, 500); // Specified by assignment
  // Initialize columns and rows
  cols = 10; // Specified by assignment | size/squareSize
  rows = 10; // Specified by assignment | size/squareSize
void draw() {
  // Begin loop for columns
  for (int i = 0; i < cols; i++) {
    // Begin loop for rows
    for (int j = 0; j < rows; j++) {
      // Scaling up to draw a rectangle at (x,y)
      int x = i*squareSize; // width
      int y = j*squareSize; // height
      // Begin fill controls
      if ((i+j) % 2 == 0) { // Even is red
        fill(250, 0, 0);
      } else { // Odd is black
      // For every column and row, a rectangle is drawn at an (x,y) location scaled and sized by videoScale.
      rect(x, y, squareSize, squareSize);
      ellipse(x,y, 40,40);  **// How do I move these to be only in the black squares?**

does it mean one circle over each black field
( like you try over every field what could work if your white is same!
means the white circle in the white fields would be not visible. )

or does it mean one circle on a specific field?

two fill commands / first black then white / not make sense
and fill fill ellipse are 3 lines???

and pls. repair your code posting using


code formatting.

The idea is to check whether you are in an even column plus uneven row or vice versa

You need an if clause :

if ((i+j) % 2 == 0)


if(i%2==0 && j%2==0) {