Ricardo
Ricardo

Reputation: 1

Sort by name Object[][] Java

I've started programming recently so this could turn be easy. I'm having a difficult in order my object. I have a object with Name, Birth Date and phone number. Like Object[0][0]="John" Object[0][1]="10/10/2010" Object[0][0]="900000000" with several other persons. So my difficult is to sort by name and keep the Birth date and phone number along with the name. Thank you.

Upvotes: 0

Views: 108

Answers (2)

camickr
camickr

Reputation: 324147

Here is my standard sorting example, which happens to use a Person object:

/*
**  Use the Collections API to sort a List for you.
**
**  When your class has a "natural" sort order you can implement
**  the Comparable interface.
**
**  You can use an alternate sort order when you implement
**  a Comparator for your class.
*/
import java.util.*;

public class Person implements Comparable<Person>
{
    String name;
    int age;

    public Person(String name, int age)
    {
        this.name = name;
        this.age = age;
    }

    public String getName()
    {
        return name;
    }

    public int getAge()
    {
        return age;
    }

    public String toString()
    {
        return name + " : " + age;
    }

    /*
    **  Implement the natural order for this class
    */
    public int compareTo(Person p)
    {
        return getName().compareTo(p.getName());
    }

    static class AgeComparator implements Comparator<Person>
    {
        public int compare(Person p1, Person p2)
        {
            return p1.getAge() - p2.getAge();
        }
    }

    public static void main(String[] args)
    {
        List<Person> people = new ArrayList<Person>();
        people.add( new Person("Homer", 38) );
        people.add( new Person("Marge", 35) );
        people.add( new Person("Bart", 15) );
        people.add( new Person("Lisa", 13) );

        // Sort by natural order

        Collections.sort(people);
        System.out.println("Sort by Natural order");
        System.out.println("\t" + people);

        // Sort by reverse natural order

        Collections.sort(people, Collections.reverseOrder());
        System.out.println("Sort by reverse natural order");
        System.out.println("\t" + people);

        //  Use a Comparator to sort by age

        Collections.sort(people, new Person.AgeComparator());
        System.out.println("Sort using Age Comparator");
        System.out.println("\t" + people);

        //  Use a Comparator to sort by descending age

        Collections.sort(people, Collections.reverseOrder(new Person.AgeComparator()));
        System.out.println("Sort using Reverse Age Comparator");
        System.out.println("\t" + people);
    }
}

Upvotes: 0

Eran
Eran

Reputation: 393956

The logical thing to do would be to create a Person class that contains name, birth date and phone number. Then, instead of using a 2D Object array, which is not type safe, use a 1D array - Person[].

If your Person class would implement Comparable<Person> (with comparison logic that compares the names), Arrays.sort() would sort the array for you by name.

Upvotes: 2

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