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Java Java Objects (Retired) Harnessing the Power of Objects Throwing Exceptions

Posted by Sarfaraj Alam
Sarfaraj Alam
14,074 Points

Code Challenge: Throwing Exception

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

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

public String getColor() { return mColor; }

public void drive() { drive(1); }

public void drive(int laps) { throw new IllegalArgumentException("Not enough battery remains");// Other driving code omitted for clarity purposes mBarsCount -= laps;

}

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

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

I am not able to find where is mistake?

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

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

  public String getColor() {
    return mColor;
  }

  public void drive() {
    drive(1);
  }

  public void drive(int laps) {
    throw new IllegalArgumentException("Not enough battery remains");// Other driving code omitted for clarity purposes
    mBarsCount -= laps;

  }

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

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

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

}

3 Answers

Grigorij Schleifer
Grigorij Schleifer
10,365 Points
Grigorij Schleifer
Grigorij Schleifer
10,365 Points

Hi Sarfaray,

you need an if statement to proof whether the amount of laps not greater then the count of bars (mBarsCount). If more laps then mBarsCount then you should throw an exception inside the if block. Otherwise decrease the mBarsCount by number of laps.

Try to do it yourself. Shout out if you need a spoiler code :)

Grigorij

Piotr Stefański
Piotr Stefański
3,080 Points
Piotr Stefański
Piotr Stefański
3,080 Points

Hello,

This is not so hard, you need to remember that, you need to throw exception only when laps are greater than mBarsCount.

So in this case you need to have following code:

public void drive(int laps){ if (laps > mBarsCount){ throw new IllegalArgumentException("Not enough battery remains"); } mBarsCount -= laps; }

Hope that helps.

Sarfaraj Alam
Sarfaraj Alam
14,074 Points
Sarfaraj Alam
Sarfaraj Alam
14,074 Points

Thank you so much