p5: conditionals / if statements

A condition like if( myVariable == true) or if(myVariable > 20) must always return a boolean value (true or false).

To construct more complex conditions for both if statements and loops we have to get into Boolean operators.

For our purposes == and === are equivalent. In javascript they compare both value and type of a variable.

Exercise

Starting from  a 9×9 pattern of green circles

var rows = 9;
var rows = 9;
var cols = 9;
var circleDiameter = 40;
var distanceX = 60;
var distanceY = 60;

function setup() {
	createCanvas(600, 600);
	noStroke();
}

function draw() {
	background(0);
	for (var r = 0; r < rows; r++) {
		for (var c = 0; c < cols; c++) {

			if (r == 0) {
				fill(200, 0, 0);
			} else {
				fill(0, 200, 0);
			}

			ellipse(c * distanceX + distanceX, r * distanceY + distanceY, circleDiameter, circleDiameter);
		}
	}
}

Reproduce the following outputs by changing only the if condition: