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Java Java Objects (Retired) Harnessing the Power of Objects Methods and Constants

Posted by djwyatt
djwyatt
13,954 Points

Java Objects / Methods and Constants Challenge Task 1 of 3

These GoKarts have a single rechargeable battery that have a display of bars to measure its energy level. Each battery has a maximum of 8 bars.

For this task, let's add a constant field to the class that stores the maximum number of energy bars. Make sure the field cannot be changed and is accessible from the class, not just the instance. Use the naming convention we learned.

GoKart.java 
public class GoKart {
  private String mColor;

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

  public String getColor() {
    return mColor;

  public class Bars {
  public static final int MAX_BARS = 8;
  private String mCharacterName;
  private int mBarsCount;
 }


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

Hey dywyatt

You are very welcome !!!

See you in the forum ...

3 Answers

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

Hi dywyatt,

allow me to comment this challenge .... 

public class GoKart {
  private String mColor;
  public static final int MAX_BARS = 8;
  // I deleted "public class Bars" because we only need to define variables here
  // public means the variable is accessible from the class, and not just the instance (so correct)
  // final: it cannot be changed (also correct)

  //TASK 2
  private int mBarsCount;
  // an uninitialized int variable


 // constructor has the same name as the class and it needs to be public
 // so you can use/access the constructor from everywhere
  public GoKart(String color) {
    mColor = color;
    mBarsCount = 0;
     // initializing means assigning a value to a variable
    // here we initialize the value 0 to mBarsCount
  }


  // a public method
  // that returns nothing (void)
  // a method need the word void, not like the constructor
  public void charge () {
    mBarsCount = MAX_BARS;
    // assigning MAX_BARS (= 8) to the mBarsCount variable
    // when you call charge() you set mBarsCount from 0 to 8 !
  }


  public String getColor() {
    return mColor;
  } 
}

Does it make sense?

Grigorij

djwyatt
djwyatt
13,954 Points

Thanks for the help, yes it does make sense! Much appreciated.

Gavin Ralston
Gavin Ralston
28,770 Points
Gavin Ralston
Gavin Ralston
28,770 Points

All you need to do in this case is add MAX_BARS as a static, final field to the GoKart class. :)

You don't need to make a Bars subclass to hold on to the constant or anything. Just put it right there in the GoKart class as a static field.

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

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

  public String getColor() {
    return mColor;

  } 
}
Muhammad Asif
PLUS
Muhammad Asif
Courses Plus Student 557 Points
Muhammad Asif
Muhammad Asif
Courses Plus Student 557 Points

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

public GoKart(String color) { this.color = color; }

public String getColor() { return color;

} }