What is this? In normal speak.

Hi Jade

OOP (object orientated programming) is tricky to grasp but very powerful once you understand the principles. I'll try to explain what is happening although truth be told explaning stuff has never been by strongest suit :) (you can always message back and i'll try to reply)

Okay so the entire block of code you have posted is a CLASS. A class is the way in which we group variables and methods together to manage data easier by creating OBJECTS. Objects and Classes is often where most people get muddled up; a class is the blueprint or instructions on how an object should work and what data an object should hold. The example I like to use is LEGO (everyone knows what lego is). A single lego brick is an object it has properties (this would be variables in programming jargon) like number of bumps, shape and colour. The mould used to make this lego piece would be the class in this example it doesn't do anything other than create objects.

Hopefully you're with me so far....

public class GoKart {
  private String mColor;
  public static final int MAX_BARS= 8;
  private int mBarsCount;

}

The code block above shows you the variables of the class, now to avoid baffling you further ignore the MAX_BARS variable as this is what we call a static constant and only confuses what I'm going to explain.

Now the class or blueprint knows how to make go karts it knows they should have a colour and a battery life percentage but it doesn't know what these will be... (if you think about it how would the factory ever know before hand how much battery life will be in a gokart and what colour it will be until the gokart is made).

So how will the class ever know which object to make? We provide ways for us to communicate to the blueprint and alter parameters in order to make a GoKart which matches our needs at that time. These are the methods....

public class GoKart {

  public GoKart(String color) {  //Constructor - This is called when we create a new GoKart OBJECT from this class
    mColor = color;
  }

  public String getColor() { //This is a method that this class gives to all objects just like the variables
    return mColor;

  } 

  public void charge (){ //This is the same as getColor()
  mBarsCount = MAX_BARS;
  }
}

Here there are 2 types of methods the one labelled as a constructor is a method we call when we create a new object from this class so at runtime we might want a 'blue' GoKart so we would create something like

GoKart myNewGoKart = new GoKart("blue");

We are saying here "I want a new GoKart object called myNewGoKart. I want it to be blue" the code goes to the GoKart class and says "hey, how do I make a GoKart? ... The GoKart class creates a new GoKart OBJECT by copying itself in effect and running the code inside the constructor (in this example being passed in the parameter blue) ... The class then comes back and says Here you go, a brand new GoKart in blue as you requested".

The second type of methods are simply methods that the class copies to the new object usually for the object to have the ability to manipulate it's own variables in order to interact with your code as you could place it anywhere.

I really hope I've explained some principles okay for you to understand but please message back if something doesn't make sense. The major benefit of splitting code up like this is it allows you to deploy these objects in numerous places within your code while only editing the code in one place so should a bug be in your code you know exactly where to look, it's confusing at first but very powerful and logical once it 'snaps' into place.

Daniel