processing bouncing ball

gistfile1.pde

int xPos = 0;

int speed = 4;

void setup(){
  size(300,300);
}

void draw(){
  background(150,150,150);
  
  xPos = xPos + speed;
  
  // || = OR  && = AND
  
  if(xPos > width || xPos < 0){
    speed = speed * -1;
  }
  
  ellipse(xPos,150,20,20);
}