// Daniel Shiffman

// http://natureofcode.com

​

let walker;

​

function setup() {

  createCanvas(640, 360);

  walker = new Walker();

  background(127);

}

​

function draw() {

  walker.step();

  walker.render();

}

​

class Walker {

  constructor() {

    this.x = width / 2;

    this.y = height / 2;

  }

​

  render() {

    stroke(0);

    point(this.x, this.y);

  }

​

  step() {

    let choice = floor(random(4));

    if (choice === 0) {

      this.x++;

    } else if (choice == 1) {

      this.x--;

    } else if (choice == 2) {

      this.y++;

    } else {

      this.y--;

    }

    this.x = constrain(this.x, 0, width - 1);

    this.y = constrain(this.y, 0, height - 1);

  }

}