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

Avery Freeman-wheaton
Avery Freeman-wheaton
2,273 Points
Posted by Avery Freeman-wheaton
Avery Freeman-wheaton
2,273 Points

bool charge increment - no error in preview, but cannot continue course

Hi,

I wrote a sequence to increment the charge of the GoKart battery by one (so I think). When I click on "check work" it doesn't show any errors in the preview window, but I am not allowed to move on. Here's the code:

public boolean charge() { boolean charging = false; if (!isFullyCharged()) { mBarsCount++; charging = true; } return charging; }

I have tried implementing a "while loop" to print the increment with:

while charging() { System.out.println(mBarsCount); }

Although I'm not sure if that would be correct (it gives me errors).

Anyway, any help would be appreciated. Thanks!

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 boolean charge() {
   boolean charging = false;
    if (!isFullyCharged()) {
    mBarsCount++;
    charging = true;
  }
  return charging;
  }


  public void charged() {
    mBarsCount = MAX_ENERGY_BARS;
  }

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

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

  public String getColor() {
    return mColor;
  }
}

2 Answers

Jon Kussmann
PLUS
Jon Kussmann
Courses Plus Student 7,254 Points
Jon Kussmann
Jon Kussmann
Courses Plus Student 7,254 Points

Hi Avery,

The idea behind the charge() method is you want to continuously increment mBarsCount as long as your GoKart is not fully charged. By using an if statement, you only check once if the GoKart is fully changed (and only increment it once if it is not).

A while loop works better for this, since it will run a block of code until it reaches false (in this case when the GoKart is fully charged).

I believe you were supposed to modify the given charge() method (it looks like you added a new method?).

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

I hope this helps. If not, let me know if I can clarify anything.

Avery Freeman-wheaton
Avery Freeman-wheaton
2,273 Points
Avery Freeman-wheaton
Avery Freeman-wheaton
2,273 Points

Hi,

Yes, this was helpful (as was the other answer, thank you!).

The example shown in the video had the while loop occurring in a different class, so it was a little confusing to me.

Here's how I implemented the code:

  public boolean charging() {
    boolean isFullyCharged = false;
    while (!isFullyCharged()) {
    mBarsCount++;
    isFullyCharged = true;
    }
    return isFullyCharged;
  }

Thanks again!

Hayes McCardell II
Hayes McCardell II
643 Points
Hayes McCardell II
Hayes McCardell II
643 Points

The exercise isn't asking you to print the output in the while loop, it wants you to actually implement the increment inside the while loop.

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

I'd suggest being careful when you change return types on methods and/or insert new variables that haven't been specified, as well.

There are two beasts to tackle here. One is the language itself, and the other is the specific requirements that the exercise is checking for. If you crank up your own IDE and fiddle with the code, some solutions might work perfectly. But if you try to put that more elegant and robust code into the exercise, it may fail because it's just seeing things it's not expecting.

Avery Freeman-wheaton
Avery Freeman-wheaton
2,273 Points
Avery Freeman-wheaton
Avery Freeman-wheaton
2,273 Points

Hi,

yes, tinkering is my nature so it's hard for me to ignore wanting to fiddle with IDEs (I set up Eclipse long before I started with TreeHouse and struggled with poor-quality tutorials on Youtube).

However, for the purposes of these exercises I am simply using workspaces in an attempt to circumvent the pitfalls of getting overly involved in the infrastructure-side of coding.

Thanks for your input, I really appreciate it.