let y = 10; //spacing between rows

let w = 5; // the width of a circle

let margin = 10; // the margin on the upperleft hand

let numC = 20; // the number of circles

​

function setup() {

  createCanvas(400, 400);

  noFill();

  noLoop(); // so that draw loop DOES NOT repeat

}

​

function draw() {

  background(255);

 for (let j = 0; j < numC;j++) {

     for (let i = 0; i < numC; i++) { // writes a row

    circle(margin + x * i, margin + y * j, w); 

       console.log(i + " is the value of i", j + " is the value of j ")

     }

  }

​

​

}

​