The add(int index, E element) method of AbstractList is used to insert an element at the specified position in this list. The new element is inserted at the specified index in this list.
Syntax:
public void add(int index, E element)
Parameters: This method takes 2 parameters :-
- index: index at which the specified element is to be inserted
- element: element to be inserted
Returns: The function returns a boolean value True if the element is successfully inserted in the List otherwise it returns False.
Exceptions:The exceptions present are :-
- ClassCastException: if the class of an element of this set is incompatible with the specified collection
- NullPointerException: if this set contains a null element and the specified collection does not permit null elements, or if the specified collection is null.
- UnsupportedOperationException: if the add operation is not supported by this list.
- IllegalArgumentException: if some property of the specified element prevents it from being added to this list.
- IndexOutOfBoundsException: if the index is out of range (index size()).
Below program illustrates the add(int index, int position) function of AbstractList class :
Program 1:
// Java code to illustrate AbstractList// add(int index, int position) method  import java.io.*;import java.util.*;  public class ArrayListDemo {    public static void main(String[] args)    {          // Create an empty list        // with an initial capacity        AbstractList<Integer> list            = new ArrayList<Integer>(5);          // Use add() method        // to add elements in the list        list.add(3);        list.add(6);        list.add(9);        list.add(12);          // Prints all the elements        // available in list        System.out.println("Before: "                           + list);          // Add(int index, int element) method        list.add(1, 4);          // Prints all the elements        // after the above method        System.out.println("After: "                           + list);    }} |
Output:
Before: [3, 6, 9, 12] After: [3, 4, 6, 9, 12]
Program 2:
// Java code to illustrate AbstractList// add(int index, int position) method  import java.io.*;import java.util.*;  public class ArrayListDemo {    public static void main(String[] args)    {          // Create an empty list        // with an initial capacity        AbstractList<String> list            = new ArrayList<String>(5);          // Use add() method        // to add elements in the list        list.add("Geeks");        list.add("for");        list.add("Computer");        list.add("Portal");          // Prints all the elements        // available in the list        System.out.println("Before: " + list);          // Add(int index, int element) method        list.add(2, "Geeks");          // Prints all the elements        // after the above method        System.out.println("After: " + list);    }} |
Output:
Before: [Geeks, for, Computer, Portal] After: [Geeks, for, Geeks, Computer, Portal]
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/AbstractList.html#add(int, %20E)
