sort by : high to low sort by: low to high

Question

Using this How to do When I put high to low or low to high it will arrange ?

String [][]Data={{"Eugine","8"},{"Ben","9"},{"John","19"},{"Jairus","5"},{"Sofia","13"}};

OUTPUT sort by : high to low John",19 Sofia,13 Ben",9 Eugine,8 Jairus,5 sort by : low to high Jairus,5 Eugine,8 Ben,9 Sofia,13 John,19

---

//This is just my noob code// //please help//
 String [][] Data={{"Eugine","8"},{"Ben","9"},{"John","19"},{"Jairus","5"},{"Sofia","13"}};
            Arrays.sort(people);
            for(Person p : people)
                System.out.println(p.name + ", " + p.age);
        }
    }

    class Person implements Comparable<Person>{
        public final String name;
        public final int age;[enter image description here][1]
        public Person(String name, int age){
            this.name = name;
            this.age = age;
        }
        @Override
        public int compareTo(Person person) {
            return age - person.age;
        }

Answer 1

Since you are trying to sort in different ways, you need to use Comparator.

Some of the ways in which you can do it are as follows:

[By creating and using separate comparators]

import java.util.Arrays;
import java.util.Comparator;

class Person {
    private String name;
    private int age;

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

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

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

class LowToHighComparator implements Comparator<Person> {

    @Override
    public int compare(Person p1, Person p2) {
        return Integer.compare(p1.getAge(), p2.getAge());
    }
}

class HighToLowComparator implements Comparator<Person> {

    @Override
    public int compare(Person p1, Person p2) {
        return Integer.compare(p2.getAge(), p1.getAge());
    }
}

public class Main {
    public static void main(String[] args) {
        Person[] people = { new Person("Eugine", 8), new Person("Ben", 9), new Person("John", 19),
                new Person("Jairus", 5), new Person("Sofia", 13) };

        Person[] lowToHigh = people.clone();
        Person[] highToLow = people.clone();

        Arrays.sort(lowToHigh, new LowToHighComparator());
        Arrays.sort(highToLow, new HighToLowComparator());

        System.out.println("Unsorted: ");
        Arrays.stream(people).forEach(System.out::println);
        System.out.println();

        System.out.println("Low to high: ");
        Arrays.stream(lowToHigh).forEach(System.out::println);
        System.out.println();

        System.out.println("High to low: ");
        Arrays.stream(highToLow).forEach(System.out::println);
    }
}

Output:

Unsorted: 
Eugine age 8
Ben age 9
John age 19
Jairus age 5
Sofia age 13

Low to high: 
Jairus age 5
Eugine age 8
Ben age 9
Sofia age 13
John age 19

High to low: 
John age 19
Sofia age 13
Ben age 9
Eugine age 8
Jairus age 5

[By using Comparator.comparing]

import java.util.Arrays;
import java.util.Comparator;

class Person {
    private String name;
    private int age;

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

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

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

public class Main {
    public static void main(String[] args) {
        Person[] people = { new Person("Eugine", 8), new Person("Ben", 9), new Person("John", 19),
                new Person("Jairus", 5), new Person("Sofia", 13) };

        Person[] lowToHigh = people.clone();
        Person[] highToLow = people.clone();

        Arrays.sort(lowToHigh, Comparator.comparing(Person::getAge));
        Arrays.sort(highToLow, Comparator.comparing(Person::getAge).reversed());

        System.out.println("Unsorted: ");
        Arrays.stream(people).forEach(System.out::println);
        System.out.println();

        System.out.println("Low to high: ");
        Arrays.stream(lowToHigh).forEach(System.out::println);
        System.out.println();

        System.out.println("High to low: ");
        Arrays.stream(highToLow).forEach(System.out::println);
    }
}

Output:

Unsorted: 
Eugine age 8
Ben age 9
John age 19
Jairus age 5
Sofia age 13

Low to high: 
Jairus age 5
Eugine age 8
Ben age 9
Sofia age 13
John age 19

High to low: 
John age 19
Sofia age 13
Ben age 9
Eugine age 8
Jairus age 5