createCanvas(400, 400);

}

​

function draw() {

  background(220);

        // counting pixel

  //   for (let x=0; x<width; x +=40){

  //     rect(x,0,40,height);

  //   }

        //counting columns 

  //   for (let c = 0 ; c<10; c++){

  //     if (c! == 6){//skip column 7

  //       let x = c*40;

  //       rect(x,0,40,height);

  //     }

  //   }

​

  // NO! possible way to make grid but not really 

  //   for (let a = 0; a<10; a++){

  //     let x = a * 40;

  //     rect(x,0,40,height);

  //   }

//CHECKERBOARD

  for (let c = 0; c <10; c++){

    let x = c *40; 

    for (let r = 0; r<10; r++){

      let y = r*40;

      //if ((c % 2 == 0 && r % 2 == 0)|| (c % 2 == 1 && r % 2 ==1 ){ %% is modular. it is combination of divide and plus. 

      if ((c + r) % 2 == 0)

      {

        fill("red");

      }else {

        fill('white');

      }

      rect (x,y,40,40)

      }

  }

​

}