Pong - problems with boundary check

Processing Coding Questions
9

I have added this to checkBoundaries to check for collisions between the ball and paddle: (100 is the length of the paddle, I’ll move that to a constant later )

for(float index = paddle.x; index < paddle.x + 100; index++) {
      if(xPos == index) {
       ySpeed = abs(ySpeed) * -1;
      }
    }

But I am getting null pointer exception. Where did I go astray here?

Does processing have a simpler way to check collisions?

Thanks,
Marc