List add(int index, E element) method in Java

Last Updated : 03 Dec, 2024

The add(int index, E ele) method of List interface in Java is used to insert the specified element at the given index in the current list.

Implementation:

Java

// Java code to illustrate add(int index, E elements)
import java.util.*;

public class ArrayListDemo 
{
    public static void main(String[] args)
    {
        // Creating List
        List<String> l = new ArrayList<String>(5);

        // Adding element in List
        l.add("Geeks");
        l.add("For");
        l.add("Geeks");
      
        // use add() method to initially
        // add elements in the list
        l.add(0, "Hello");
      
      	// Printing elements
        for (String str : l) {
            System.out.print(str + " ");
        }
    }
}

Output

Hello Geeks For Geeks

Syntax of Method

public add(int index, E element)

Parameter: This method accepts two parameters as shown in the above syntax:

index: This parameter specifies the index at which we the given element is to be inserted.
element: This parameter specifies the element to insert in the list.

Return Value: Boolean and it returns true if the object is added successfully.

Exceptions:

UnsupportedOperationException - It throws this exception if the add() operation is not supported by this list.
ClassCastException - It throws this exception if the class of the specified element prevents it from being added to this list.
NullPointerException - It throws this exception if the specified element is null and this list does not permit null elements.
IllegalArgumentException - It throws this exception if some property of this element prevents it from being added to this list.

Example of List add() Method

Below programs illustrate the List.add(int index, E element) method:

Java

// Java code to illustrate add(int index, E elements)
import java.util.*;

public class ArrayListDemo 
{
    public static void main(String[] args)
    {

        // Create an empty list
        List<Integer> l = new ArrayList<Integer>(5);

        // Adding Elements in List 
      	l.add(10);
        l.add(20);
        l.add(30);

        // Add a new  25 at index 2 and print true
        // if the element is added successfully
        System.out.println(l.add(2, 25));

        // Prints element of List
        for (Integer num : l) {
            System.out.print(num + " ");
        }
    }
}