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Java Java Objects (Retired) Harnessing the Power of Objects Incrementing

Niyamat Almass
Niyamat Almass
8,176 Points
Posted by Niyamat Almass
Niyamat Almass
8,176 Points

I have a problem

I done the challenge.But a error.The error code is below

./GoKart.java:29: error: cannot find symbol while (!isEmpty()) { ^ symbol: method isEmpty() location: class GoKart 1 error

GoKart.java 
public class GoKart {
  public static final int MAX_ENERGY_BARS = 8;
  private String mColor;
  private int mBarsCount;

  public GoKart(String color) {
    mColor = color;
    mBarsCount = 0;
  }

  public String getColor() {
    return mColor;
  }

  public void charge() {
    mBarsCount = MAX_ENERGY_BARS;
  }

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

  public boolean isFullyCharged() {
    return mBarsCount == MAX_ENERGY_BARS;
  }

  public boolean isCharged() {
    boolean isCharged = false;
    while (!isEmpty()) {
       mBarsCount--;
      isCharged = true;
    }
   return isCharged; 
  }

}
Jose Cortedano
Jose Cortedano
409 Points
Jose Cortedano
Jose Cortedano
409 Points

Niyamat Almas, please take a look again. You are calling a method that does not exist in your code. You cannot boolean isEmpty if the method has nothing to (!). I think you meant to call isBatteryEmpty() not isEmpty. Good luck!

Niyamat Almass
Niyamat Almass
8,176 Points
Niyamat Almass
Niyamat Almass
8,176 Points

thank you Jose Cortedano

1 Answer

Rebecca Bompiani
Rebecca Bompiani
16,948 Points
Rebecca Bompiani
Rebecca Bompiani
16,948 Points

Hi Niyamat-

You're getting that error because isEmpty() is not a method defined in your code.

For this challenge, what you'll want to do is alter the existing charge() method. We need to update the code with the following logic: while the battery is not fully charged (we can check this using our previous isFullyCharged() method), add one to mBarsCount

Try this:

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

  public GoKart(String color) {
    mColor = color;
    mBarsCount = 0;
  }

  public String getColor() {
    return mColor;
  }


  public void charge() {
    // new/updated code goes here!
    while(!isFullyCharged()){
    mBarsCount++;
    }    
  }

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

  public boolean isFullyCharged() {
    return mBarsCount == MAX_ENERGY_BARS;
  }

}
Niyamat Almass
Niyamat Almass
8,176 Points
Niyamat Almass
Niyamat Almass
8,176 Points

Thank you!!!!!!! I solve the challenge.