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

Okay, so let's use our new isFullyCharged helper method to change our implementation details of the charge method. Let's

i did not understand the quetion

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;


2 Answers

Anish, TH wants you to rewrite the charge() method so it uses the isFullyCharged() method instead of just setting mBarsCount to the max number of bars.:

  public void charge() {
    while (!isFullyCharged()) {

Here mBarsCount is incremented in a while loop as long as isFullyCharged() is not (!) true.

I'm stuck too and tried this, but it did not work. Anyone else have any ideas?

Florian Tönjes
.a{fill-rule:evenodd;}techdegree seal-36
Florian Tönjes
Full Stack JavaScript Techdegree Graduate 50,856 Points

Hey Anish,

in this challenge you have a GoKart class that implements the 'charge' method.

The challenge wants you to change the method, so that it does use a while loop which checks if the battery is full by using the "isFullyCharged" method. If it is not (! - is the symbol for not) mBarsCount should be incremented (increased in steps).

  public void charge() {
    // use while(), isFullyCharged() and '!' symbol in this method now.

Kind Regards, Florian