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Java Java Objects Harnessing the Power of Objects Increment and Decrement

Posted by mathieu combaudon
mathieu combaudon
Courses Plus Student 14,894 Points

im stuck on ths one , anyone to help?

i don(t get the point, how should i decrement in the drive function?

GoKart.java 
class GoKart {
  public static final int MAX_BARS = 8;
  private String color;
  private int barCount;

  public GoKart(String color) {
    this.color = color;
  }

  public String getColor() {
    return color;
  }

  public void charge() {
    barCount = MAX_BARS;
  }

  public boolean isBatteryEmpty() {
    return barCount == 0;
  }

  public boolean isFullyCharged() {
    return MAX_BARS == barCount;
  }
  private int lapsDriven;

  public void drive(){
    lapsDriven++;
    barCount--; 
     }

    }
  }
}
Douglas Carvalho
Douglas Carvalho
5,056 Points
Douglas Carvalho
Douglas Carvalho
5,056 Points

I don't know if I got exactly what you want to know, but your drive method seems correct. It means that for each lap you complete, one less to go. But one thing that is missing is the lapsDriven class attribute.

1 Answer

Cameron Hastings
Cameron Hastings
3,439 Points
Cameron Hastings
Cameron Hastings
3,439 Points

In the first task, you should add a new private int field called lapsDriven. I see you have it, but in a weird place. So, like this:

Solution to first task:

GoKart.java 
class GoKart {
  public static final int MAX_BARS = 8;
  private String color;
  private int barCount;
  private int lapsDriven; // <---- this is what you need.

For the second and third task, create a new method called 'drive' (that doesn't return anything), increment the new lapsDriven variable by 1. Decrement the battery by 1 every lap. Use the incrementing shorthand to increase lapsDriven and decrease batteryCount.

So first create the method. It is void, because it doesn't return anything. Looks like this:

GoKart.java 
 public void drive() {

}

Then within the drive method, set lapsDriven = 0; and barCount = MAX_BARS. After that, add an if statement. "If the battery is not empty, add 1 to lapsDriven and subtract barCount by 1" Looks like this:

Solution to task 2 and 3:

GoKart.java 
 public void drive() {
    lapsDriven = 0;
    barCount = MAX_BARS;
    if (!isBatteryEmpty()) {
      lapsDriven++;
      barCount--;
    }
  }

Hope this helped.