List - Insertion order

May 05, 2016

List interface keeps the order of insertion of elements i.e. the order in which the elements added to the list will remain in same order after any operation. Every addition takes the index of last inserted element plus one (last index + 1).

package net.raj.test;

import java.util.ArrayList;
import java.util.List;

public class ArrayListImpl {

    public static void main(String[] args) {
        // Declare an ArrayList
        List&lt;String&gt; list = new ArrayList&lt;&gt;();

        list.add("one");
        list.add("two");
        list.add("three");
        list.add("four");

        System.out.println("Sample ArrayList 1:: " + list.toString());

        // Reuse the same object
        // list keeps the order
        list = new ArrayList&lt;&gt;();

        list.add("three");
        list.add("four");
        list.add("one");
        list.add("two");

        System.out.println("Sample ArrayList 2:: " + list.toString());
    }
}