Using the Comparable interface to compare and sort objects : Comparator « Collections Data Structure « Java






Using the Comparable interface to compare and sort objects

    

import java.util.Arrays;

public class Main {
  public static void main(String[] args) {
    Car car1 = new Car("A",  5000);
    Car car2 = new Car("B", 5000);
    Car car3 = new Car("C", 4000);

    System.out.println("Car 1 equals Car 2: " + car1.compareTo(car2));
    System.out.println("Car 1 equals Car 3: " + car1.compareTo(car3));
    System.out.println("Car 2 equals Car 3: " + car2.compareTo(car3));

    Car[] carArray = new Car[] { car1, car2, car3 };
    Arrays.sort(carArray);

    for (Car car : carArray)
      System.out.println(car.toString());
  }
}

class Car implements Comparable {
  private String make;

  private int mileage;

  public Car(String make, int mileage) {
    this.make = make;
    this.mileage = mileage;
  }

  public int compareTo(Object obj) {
    if (obj instanceof Car) {
      Car car = (Car) obj;
      if (this.mileage > car.getMileage())
        return 1;
      else if (this.mileage < car.getMileage())
        return -1;
    }
    return 0;
  }

  public int getMileage() {
    return mileage;
  }

  public String toString() {
    StringBuffer buffer = new StringBuffer();
    buffer.append("Make: " + make + ",Mileage: " + mileage);
    return buffer.toString();
  }
}

   
    
    
    
  








Related examples in the same category

1.Creating a Comparable objectCreating a Comparable object
2. Writing Your own Comparator Writing Your own Comparator
3.A Class Implementing Comparable
4.Comparator for comparing strings ignoring first character
5.List and Comparators
6.Sort backwards
7.Company and Employee
8.Search with a Comparator
9.Keep upper and lowercase letters togetherKeep upper and lowercase letters together
10.Uses anonymous inner classesUses anonymous inner classes
11.Building the anonymous inner class in-placeBuilding the anonymous inner class in-place
12.Sort an array of strings in reverse order.
13.Sort an array of strings, ignore case difference.
14.Comparator uses a Collator to determine the proper, case-insensitive lexicographical ordering of two strings.
15.Sort on many(more than one) fields
16.File Name Comparator
17.Comparator similar to String.CASE_INSENSITIVE_ORDER, but handles only ASCII characters
18.Natural Order Comparator
19.Reverse Order Comparator
20.A Comparator for Boolean objects that can sort either true or false first
21.Invertible Comparator
22.This program animates a sort algorithm