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

Peter Kurkowski
Peter Kurkowski
595 Points
Posted by Peter Kurkowski
Peter Kurkowski
595 Points

Not sure where to start with this while loop question.

The question is:

"Okay, so let's use our new isFullyCharged helper method to change our implementation details of the charge method. Let's make it so it will only charge until the battery reports being fully charged. Let's use the ! symbol and a while loop. Inside the loop increment mBarsCount."

I honestly dont even know where to begin with this. Any help is appreciated.

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;
  }

}
Mark Miller
Mark Miller
45,831 Points
Mark Miller
Mark Miller
45,831 Points

The charge() method needs a while loop, where you will use the not operator ! and the helper method isFullyCharged() to make the test condition for the while loop. Increment mBarsCount while it is not fully charged. The newly modified method now performs a real reloading, instead of a forceful assignment.

1 Answer

Kaitlyn Brown
Kaitlyn Brown
1,072 Points
Kaitlyn Brown
Kaitlyn Brown
1,072 Points

I don't "speak" Java specifically - not for a long time now, anyway - but I can help you through the logic. As you learn to program, you will start to find it easier to "translate" everyday words into programming notation. In this case, "Let's make it so it will only charge until the battery reports being fully charged" translates to, "Charge while the battery is not fully charged." So you're going to use the while keyword with the !isFullyCharged condition (because you only want things to happen when it's not fully charged, which is why you use the !). Then, inside the loop, just write a single line to increment mBarsCount, which probably looks something like mBarsCount++

See if you can take that logic and put it into Java syntax! I'm sure some other nice commenter here is more familiar with the syntax than I am if you get stuck.

Peter Kurkowski
Peter Kurkowski
595 Points
Peter Kurkowski
Peter Kurkowski
595 Points

You did a great job at explaining this. This worked for me. Being new to this is proving to be difficult! Almost every challenge i need to get help.

public void charge() { while (!isFullyCharged()) { mBarsCount++; } }