The code inside the
draw() function runs continuously from top to bottom until the program is stopped. The code in
setup() is run once when the program starts.
let y = 100;
// The statements in the setup() function
// execute once when the program begins
function setup() {
// createCanvas must be the first statement
createCanvas(720, 400);
stroke(255); // Set line drawing color to white
frameRate(30);
}
// The statements in draw() are executed until the
// program is stopped. Each statement is executed in
// sequence and after the last line is read, the first
// line is executed again.
function draw() {
background(0); // Set the background to black
y = y - 1;
if (y < 0) {
y = height;
}
line(0, y, width, y);
}​
