Re: How treeMap works?

Sanny wrote


import java.util.Comparator;

public class CarComparisons {

  public static void main(String[] args) {

    Car car1 = new Car();
    //What is the value of car1?

    boolean comparison1 = (car1 == null);
    //What is the value of comparison1?
    boolean comparison2 = (car1 == car1);
    //What is the value of comparison2?
    boolean comparison3 = (car1.equals(null));
    //What is the value of comparison3?
    boolean comparison4 = (car1.equals(car1));
    //What is the value of comparison4?

    IntegerCar car2 =
      new IntegerCar(Integer.valueOf(1));
    //What is the value of car2?
    car2.setNumber(Integer.valueOf(2));
    //What is the value of car3?
    IntegerCar car3 =
      new IntegerCar(Integer.valueOf(2));
    // What is the value of car3

    boolean comparison5 = car2.equals(car3);
    //What is the value of comparison4?
    int comparison6 =
      car2.getNumber().compareTo(car3.getNumber());
    // What is the value of comparison6?

    IntegerValueComparableCar car5 =
      new IntegerValueComparableCar(Integer.valueOf(1));
    IntegerValueComparableCar car6 =
      new IntegerValueComparableCar(Integer.valueOf(2));
    int comparison9 = (car5.compareTo(car6));
    // What is the value of comparison9?
    car5.setNumber(Integer.valueOf(2));
    int comparison10 = (car5.compareTo(car6));
    // What is the value of comparison10?

    TwoValueCar car7 =
      new TwoValueCar(Integer.valueOf(1), "chevrolet");
    TwoValueCar car8 =
      new TwoValueCar(Integer.valueOf(2), "ford");

    NumberComparator numberComparator =
      new NumberComparator();
    NameComparator nameComparator =
      new NameComparator();
    NumberNameComparator numberNameComparator =
      new NumberNameComparator(false);

    TwoValueCar[] carArray = {car7, car8};

    // now it's play time
    // make some Sets, Lists, Maps
    // add, remove, iterate, compare, find, etc...

  }

  public static class Car
  extends Object {

  }

  public static class IntegerCar
  extends Car {

    private Integer number;

    public IntegerCar(Integer number) {
      this.number = number;
    }

    public Integer getNumber() {
      return number;
    }

    public void setNumber(Integer number) {
      this.number = number;
    }

  }

  public static class IntegerValueComparableCar
  extends IntegerCar
  implements Comparable<IntegerCar> {

    public IntegerValueComparableCar(Integer number) {
      super(number);
    }

    @Override
    public int compareTo(IntegerCar that) {
      return super.number.compareTo(that.number);
    }

  }

  public static class TwoValueCar
  extends IntegerCar {

    String name;

    public TwoValueCar(Integer number) {
      super(number);
      this.name = "chevrolet";
    }

    public TwoValueCar(Integer number, String name) {
      super(number);
      this.name = name;
    }

    public Integer getNumber() {
      return super.number;
    }

    public String getName() {
      return name;
    }

    public void setNumber(Integer number) {
      super.number = number;
    }

    public void setName(String name) {
      this.name = name;
    }

  }

  public static class NumberComparator
  implements Comparator<TwoValueCar> {

    @Override
    public int compare(TwoValueCar car0, TwoValueCar car1) {
      return car0.getNumber().compareTo(car1.getNumber());
    }

  }

  public static class NameComparator
  implements Comparator<TwoValueCar> {

    @Override
    public int compare(TwoValueCar car0, TwoValueCar car1) {
      return car0.getName().compareTo(car1.getName());
    }

  }

  public static class NumberNameComparator
  implements Comparator<TwoValueCar> {

    private final boolean compareByNumber;

    public NumberNameComparator(boolean compareByNumber) {
      this.compareByNumber = compareByNumber;
    }

    @Override
    public int compare(TwoValueCar car0, TwoValueCar car1) {
      if (compareByNumber) {
        return car0.getNumber().compareTo(car1.getNumber());
      }
      else {
        return car0.name.compareToIgnoreCase(car1.name);
      }

    }

  }

  public static class CarDriver {
    public final String height;
    public CarDriver(String height) {
      this.height = height;
    }
  }

}