ArrayList set() method in Java with Examples

The set() method of java.util.ArrayList class is used to replace the element at the specified position in this list with the specified element.

Syntax:

public E set(int index, E element)

Parameters: This method takes the following argument as a parameter.

• index- index of the element to replace
• element- element to be stored at the specified position

Returns Value: This method returns the element previously at the specified position.

Exception: This method throws IndexOutOfBoundsException if the index is not within the size range of the ArrayList.

Below are the examples to illustrate the set() method.

Example 1:

// Java program to demonstrate
// set() method
// for Integer value

import java.util.*;

public class GFG1 {
    public static void main(String[] argv) throws Exception
    {
        try {

            // Creating object of ArrayList<Integer>
            ArrayList<Integer>
                arrlist = new ArrayList<Integer>();

            // Populating arrlist1
            arrlist.add(1);
            arrlist.add(2);
            arrlist.add(3);
            arrlist.add(4);
            arrlist.add(5);

            // print arrlist
            System.out.println("Before operation: "
                               + arrlist);

            // Replacing element at the index 3 with 30
            // using method set()
            int i = arrlist.set(3, 30);

            // Print the modified arrlist
            System.out.println("After operation: "
                               + arrlist);

            // Print the Replaced element
            System.out.println("Replaced element: "
                               + i);
        }

        catch (IndexOutOfBoundsException e) {
            System.out.println("Exception thrown: "
                               + e);
        }
    }
}

Output:

Before operation : [1, 2, 3, 4, 5]
After operation : [1, 2, 3, 30, 5]
Replaced element : 4

Example 2: For IndexOutOfBoundsException

// Java program to demonstrate
// set() method
// for IndexOutOfBoundsException

import java.util.*;

public class GFG1 {
    public static void main(String[] argv) throws Exception
    {
        try {

            // Creating object of ArrayList<Integer>
            ArrayList<Integer>
                arrlist = new ArrayList<Integer>();

            // Populating arrlist1
            arrlist.add(1);
            arrlist.add(2);
            arrlist.add(3);
            arrlist.add(4);
            arrlist.add(5);

            // print arrlist
            System.out.println("Before operation : "
                               + arrlist);

            // Replacing element at the index 7 with 30
            // using method set()
            System.out.println("\nTrying to Replace"
                               + " the element at"
                               + " (index > Capacity) ");
            int i = arrlist.set(7, 30);

            // Print the modified arrlist
            System.out.println("After operation: "
                               + arrlist);

            // Print the Replaced element
            System.out.println("Replaced element: "
                               + i);
        }

        catch (IndexOutOfBoundsException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}

Output:

Before operation : [1, 2, 3, 4, 5]

Trying to Replace the element at (index > Capacity) 
Exception thrown : java.lang.IndexOutOfBoundsException: Index: 7, Size: 5