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Java Java Objects (Retired) Harnessing the Power of Objects Method Signatures

Helen King
Helen King
9,717 Points

Code Challege help! Method Signatures

I can not figure this one out....

https://teamtreehouse.com/library/java-objects/harnessing-the-power-of-objects/method-signatures-2

I have added a method drive that defines a parameter laps. These high-powered GoKarts use 1 energy bar off their battery each lap. Using method signatures, add a new method called drive that performs just 1 lap and takes no arguments.

I've attached my code. What am i doing wrong with the drive(1)?

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(int laps) {
    // Other driving code omitted for clarity purposes
    mBarsCount -= laps;
  }

  public String drive(1){
    mBarsCount--; 
  }

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

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

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

}
Helen King
Helen King
9,717 Points

Thank you! I swear I tried that and it didn't work, maybe it was glitching out on me. I get a lot of communication errors! I appreciate the help :)

5 Answers

Kourosh Raeen
Kourosh Raeen
23,732 Points

Hi Helen - The drive() method shouldn't take any arguments. Inside the method, call the other drive method that takes an int an pass 1 to it.

Kourosh Raeen
Kourosh Raeen
23,732 Points

That's ok. So we need to create another drive method. It's return type is going to be void like the other one, but it doesn't take any parameters. So it will look like this:

public void drive() {
   // now call the other drive method with an argument of 1 passed in
}

See if you can figure out the line of code that goes after the comment I left in the code. Let me know if you need more help.

Helen King
Helen King
9,717 Points

i've tried adding

drive = 1; drive (1); return drive (1);

while drive(int laps){ drive = 1; }

I'm probably majorly overthinking this :( I guess i'm not understanding how to call the other method

Kourosh Raeen
Kourosh Raeen
23,732 Points

drive(1); is the one you want. It calls the other drive method with an argument of 1, which results in performing just 1 lap. You don't want the return since the method is void and not returning anything. You also don't want drive = 1; because this is assigning 1 to a variable called drive and not a function call. So, the complete code looks like this:

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(int laps) {
    // Other driving code omitted for clarity purposes
    mBarsCount -= laps;
  }

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

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

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

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

}
Helen King
Helen King
9,717 Points

Yeah I can't get my head around this one, I can't visualize it at all. I don't see where to add the other drive method

Oh man this was driving me up the wall. Thank you for the help

Joseph Richardson
Joseph Richardson
5,909 Points

This entire lessons wording on its questions are just confusing. It needs to be rewritten .