Hi guys, I was trying to sort an arrayList using a comparator but I didn't have much luck, or at least it seems like there is something slightly wrong with it.
I have these objects in the arrayList

employeeCollection.add(new Employee("Dan", 112));
employeeCollection.add(new Employee("Tim", 2));
employeeCollection.add(new Employee("Rick", 11));
employeeCollection.add(new Employee("Jack", 19));
employeeCollection.add(new Employee("Sid", 1));

and before sorting I have this

Name: Dan: 
ID number: 112:
Name: Tim: 
ID number: 2:
Name: Rick: 
ID number: 11:
Name: Jack: 
ID number: 19:
Name: Sid: 
ID number: 1:

and after sorting I have this:

Name: Dan: 
ID number: 112:
Name: Jack: 
ID number: 19:
Name: Rick: 
ID number: 11:
Name: Sid: 
ID number: 1:
Name: Tim: 
ID number: 2:

so it didn't go that well. Here is the code I've used, and the questions are:
-why isn't this sorted properly?
-what would I need to do to sort it in ascending order

/*
 * This tests Array list of employees*/
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class TestCollections {
    private static List<Employee> employeeCollection = new ArrayList<Employee>();

    public static void main(String[] args) {
        createEmployees();

    }

    private static void createEmployees() {
//      for(int i = 0; i < 10; i++) {
//          Employee employee = new Employee("Jo_" + i, i);
//          employeeCollection.add(employee);
//      }
        employeeCollection.add(new Employee("Dan", 112));
        employeeCollection.add(new Employee("Tim", 2));
        employeeCollection.add(new Employee("Rick", 11));
        employeeCollection.add(new Employee("Jack", 19));
        employeeCollection.add(new Employee("Sid", 1));

        printEmployees();

        //Collections.sort(employeeCollection);
        // Sorting
        Collections.sort(employeeCollection, new Comparator<Employee>() {
            @Override
            public int compare(Employee employee, Employee employee1)
            {

                return  employee.getName().compareTo(employee1.getName());
            }
        });

        printEmployees();
    }

    private static void printEmployees() {
        employeeCollection.forEach(listItem -> System.out.println(listItem));

    }

}

and the Employee class

public class Employee {

    private String name;
    private int idNumber;

    public Employee(String name, int idNumber) {    
        this.name = name;
        this.idNumber = idNumber;
    }

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getIdNumber() {
        return idNumber;
    }
    public void setIdNumber(int idNumber) {
        this.idNumber = idNumber;
    }

    @Override
    public String toString() {
        return String.format("%s: %s: \n%s: %d:", "Name", getName(), "ID number", getIdNumber());
    }

    // Overriding the compareTo method
   public int compareTo(Employee employee) {
      return (this.name).compareTo(employee.name);
   }

   // Overriding the compare method to sort the age 
   public int compare(Employee employee, Employee employee1) {
      return employee.idNumber - employee1.idNumber;
   }
}

What'ss the problem?
You sort the collection based on the names, and you get your collection sorted in name order.
What did you expect?

ps: Your two "override" comments are wrong - those methods override nothing (which is why you haven't been able to annotate them)

commented: Doh! Yes, I'm ordering them by name and not by value - sorry I was evidently very tired when I posted this. +7

ANd yes, those two overriden methods are not doing anything, it was just something else I was trying intead of doing the way I did it in the end - which I didn't really like it anyway.

Yes. Probabuy the nicest way to do this is to use Comparator.comparing with a Java 8 lambda eg

Collections.sort(employeeCollection, Comparator.comparing(Employee::getName));

(although personally I would be tempted toimport static so the statement becomes

Collections.sort(employeeCollection, comparing(Employee::getName));

(how readable is that!)

those two overriden methods are not doing anything,

My point was not that they were not used, it was that they are not overriding anything.

commented: MY EYES! THE GOGGLES DO NOTHING! +15