Thread: Java abstracts

For the code belong, I'm trying to compare all the objects with each other and print if they're the same, is there any efficient methods in doing so beside me creating like 20 if else statement and compare each object individually? Thanks

import java.util.*;
public class TestHomework3
{
    public static void main(String[]args)
    {
        List<Homework3>  workArray= new ArrayList<Homework3>();
        MyMath3 math = new MyMath3();
        MyScience3 science = new MyScience3();
        MyEnglish3 english = new MyEnglish3();
        MyJava3 java = new MyJava3();
        workArray.add(math);
        workArray.add(science);
        workArray.add(english);
        workArray.add(java);
 
        math.createAssignment(4);
        science.createAssignment(6);
        english.createAssignment(4);
        java.createAssignment(5);
 
        for(int x = 0 ; x < workArray.size();x++)
        {   
            System.out.println(workArray.get(x).toString());
        }
 
            if(workArray.get(0).compareTo(workArray.get(1)) == 0 )
                System.out.println("The same");
            else
                System.out.println("Differents");
 
 
    }
}

Would the List that I created with the objects being added fine or do I need to create a different array? Thanks

This is the nested loop that I have but it also compare the objects to itself since x and i have the same value at some point. How can I avoid the objects inside the list comparing itself? Thanks

    for(int x = 0 ; x < workArray.size();x++)
        {   
            System.out.println(workArray.get(x).toString());
            for(int i = 0 ; i < workArray.size();i++)
            {
                if(workArray.get(x).compareTo(workArray.get(i)) == 0 )
                    System.out.println(workArray.get(x).getType()+"The same"+workArray.get(i).getType());   
            }
        }

The print out is
"Math - must read 4 pages.
MathThe sameMath
MathThe sameEnglish
Science - must read 6 pages.
ScienceThe sameScience
English - must read 4 pages.
EnglishThe sameMath
EnglishThe sameEnglish
Java - must read 5 pages.
JavaThe sameJava
"
You can see it the objects is comparing itself to itself.

I understand the starting at another index part but let say I put i=1 instead of 0 , it might not compare itself to thing at index 0 but at index 1 and so on it will compare itself.

The second indexes should be 1 more than the first, am I correct?

--- Update ---

It work when I set i = x+1. Is this the correct way? Thanks