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

What am I doing wrong with the charge() method?

I am trying to only charge the battery when mBarsCount does not equal full bars. When the charge method is called, I want to increment the battery charge until it is at full capacity. I don't see what my code is doing wrong. Please help.

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() {
    while(!mBarsCount.isFullyCharged()) {

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

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


2 Answers

Francisco Navarro
Francisco Navarro
14,185 Points

Hi Austin,

It seems like you are calling isFullyCharged() in the wrong way. The isFullyCharged()'s method belong to GoKart's class, so try to call it with "this" instead of mBarsCount.isFullyCharged():

while(!this.isFullyCharged()){ mBarsCount++; }

Hope that helps

Thank you! This worked!

likewise, you dont even need to type "this" you could simply just do while(!isFullyCharged())

(had to ask my brother on that one, he gave me a hand in explaining why it worked. As I understand,

when you type "this" you are referring to this class. (please correct me if i'm wrong :P)

It seems that both ways work.

yep! i found that out too, i was surprised! im trying to figure all this out, and why everything works the way it does!