Hi there,

I recently started working through the Processing examples in a book called "Programming Interactivity" by Joshua Noble. It's an excellent book but unfortunately there seem to be a lot of typos (the errata is rapidly becoming as long as the book).

The code example reads as follows:

class Point{
  float x;
  float y;

  Point(float _x, float _y){
    x = _x;
    y = _y;
  }
 
  Point[] pts = new Point[6];
  int count = 0;
  void setup(){
    size(500, 500);
  }
 
  void draw(){
    background(255);
    fill(0);
    beginShape();
    for(int i = 0; i<pts.length; i++){
    if(pts[i] != null{
     vertex(pts[i].x, pts[i].y);
      }
    }
    endShape();
  }
  void mousePressed(){
    if(count > 5){
      count = 0;
    }
    Point newPoint = new Point(mouseX, mouseY);
    pts[count] = newPoint;
    count++;
  }
  class Point{
    float x;
    float y;
    Point(float _x, float _y){
      x = _x;
      y = _y;
    }
  }

The error Processing throws up is "unexpected token: null".

Thanks in advance for any help.