How can I sort an ArrayList of Strings in Java?

Question

I have Strings that are put into an ArrayList randomly.

private ArrayList teamsName = new ArrayList();
         


        

Answer 1

Check Collections#sort method. This automatically sorts your list according to natural ordering. You can apply this method on each sublist you obtain using List#subList method.

private List<String> teamsName = new ArrayList<String>();
List<String> subList = teamsName.subList(1, teamsName.size());
Collections.sort(subList);

Answer 2

Collections.sort(teamsName.subList(1, teamsName.size()));

The code above will reflect the actual sublist of your original list sorted.

Answer 3

You can use TreeSet that automatically order list values:

import java.util.Iterator;
import java.util.TreeSet;

public class TreeSetExample {

    public static void main(String[] args) {
        System.out.println("Tree Set Example!\n");

        TreeSet <String>tree = new TreeSet<String>();
        tree.add("aaa");
        tree.add("acbbb");
        tree.add("aab");
        tree.add("c");
        tree.add("a");

        Iterator iterator;
        iterator = tree.iterator();

        System.out.print("Tree set data: ");

        //Displaying the Tree set data
        while (iterator.hasNext()){
            System.out.print(iterator.next() + " ");
        }
    }

}

I lastly add 'a' but last element must be 'c'.

Answer 4

You might sort the helper[] array directly:

java.util.Arrays.sort(helper, 1, helper.length);

Sorts the array from index 1 to the end. Leaves the first item at index 0 untouched.

See Arrays.sort(Object[] a, int fromIndex, int toIndex)

Answer 5

Take a look at the Collections.sort(List<T> list).

You can simply remove the first element, sort the list and then add it back again.