var stars = [];

​

function setup() {

  createCanvas(700, 400);

    for (var i = 0; i < 30; i++) {

        stars[i] = new Star();

    }

}

​

function draw() {

  background(30);

    for (var i = 0; i < stars.length; i++) {

        stars[i].draw();

    }

}

​

​

// star class //

class Star {

    constructor() {

        this.x = random(width);

        this.y = random(height);

        this.size = random(0.25, 5);

        this.t = random(TAU);

    }

    draw() {

        this.t += 0.03;

        var scale = this.size + sin(this.t) * 2;

        noStroke();

        ellipse(this.x, this.y, scale, scale);

    }

}

​