Question

How can I use the code I have now with an object where I can store the number of times the ball bounces and the color (when i add random color) and speed. Any pointers or tips would be greatful. I am new to OOP and it can get confusing for me. Thanks in advance

  float x;
  float y;
  float yspeed = 0;
  float xspeed = 0;
  float balldiameter = 10;
  float ballradius = balldiameter/2;

  void setup() {
  size (400,400);
  background (255);
  fill (0);
  ellipseMode(CENTER);
  smooth();
  noStroke();
  x = random(400);
  y = 0;
  }

  void draw() {
  mouseChecks();
  boundaryChecks();
  ballFunctions();
  keyFunctions();
  }

  void mouseChecks() {
    if (mousePressed == true) {
    x = mouseX;
    y = mouseY;
    yspeed = mouseY - pmouseY;
    xspeed = mouseX - pmouseX;
    }
  }

  void boundaryChecks() {
    if (y >= height - ballradius) {
      y = height - ballradius;
      yspeed = -yspeed/1.15;
    }
    if (y <= ballradius) {
      y = ballradius;
      yspeed = -yspeed/1.35;
    }
    if (x >= width -ballradius) {
      x = width -ballradius;
      xspeed = -xspeed/1.10;
    }
    if (x <= ballradius) {
      x = ballradius;
      xspeed = -xspeed/1.10;
     }
   }

   void ballFunctions() {
   if (balldiameter < 2) {
     balldiameter = 2;
     }
   if (balldiameter > 400) {
     balldiameter = 400;
     }
   ballradius = balldiameter/2;
   background(255); //should this be in here?
   ellipse (x,y,balldiameter,balldiameter);
   yspeed = yspeed += 1.63;
    // xspeed = xspeed+=1.63;
   y = y + yspeed;
   x = x + xspeed; 
   }
  void keyFunctions() {
    if (keyPressed) {
      if(keyCode == UP) {
      balldiameter +=1;
    }
    if (keyCode == DOWN) {
      balldiameter -=1;
      }
    }
   }

Answer 1

you will probably want to do the following:
create a new file called Ball.pde
In that file write:

public class Ball {
    public float x;
    public float y;
    public float yspeed;
    public float xspeed;
    public float diameter;
    public float radius;  

    public Ball(float initial_x, float initial_y, float diam) {
        this.x = initial_x;
        this.y = initial_y;
        this.xspeed = 0;
        this.yspeed = 0;
        this.diameter = diam;
        this.radius = diam/2;
    }

    public void move() {
       // movement stuff here
    }
}

This will give you a very basic Ball class. You can now use this class in your main sketch file like so:

Ball my_ball = new Ball(50, 50, 10);

you can access the balls members using:

my_ball.xspeed;
my_ball.yspeed;
my_ball.anything_you_defined_in_ball;

This will allow you yo store all relevent variables for the ball within its own class. you can even create more than 1.

Ball my_ball1 = new Ball(50, 50, 10);
Ball my_ball2 = new Ball(20, 20, 5);