Sorting ArrayList

[Skanda Raman]

Please let me know how to sort the data in the below array list.

 import java.util.*;

public class SortList {

    public static void main(String args[]){
        ArrayList A1=new ArrayList();
        ArrayList A2=new ArrayList();
        ArrayList A3=new ArrayList();
        ArrayList A5=new ArrayList();
        
        A1.add("13");A1.add("America");  
        A2.add("123");A2.add("India");
        A5.add("225");A5.add("Europe");
          
        
        A3.add(A1);
        A3.add(A2);
        A3.add(A5);
        
        for(int i=0;i<A3.size();i++){
            ArrayList A4=(ArrayList)A3.get(i);         
            System.out.println(A4.get(0)+"||"+A4.get(1));
        }
        
    }
}
   

I know that we can put A4.get(0) and A4.get(1) in TreeSet and sort the list, but can the list be sorted just using above code like,

I used Collections.sort(A4) it is giving wrong results. Also, while using Collections.sort(A4), is the list sorted by taking A4.get(0) as a reference or A4.get(1) as reference.

Please let me know>

[Campbell Ritchie]

What are you getting? How are you sorting? Remember Collections#sort takes Comparable as its parameter, and I don't think Lists are usually Comparable. Strings are however, so you should be able to sort a List<String>.
Remember the order Strings are sorted in: ASCIIbetical.