In C#, an ArrayList stores elements of multiple data types whose size can be changed dynamically.
To create ArrayList in C#, we need to use the System.Collections namespace. Here is how we can create an arraylist in C#.
1 2 3 4 | // create an arraylist ArrayList myList = new ArrayList(); |
Here, we have created an arraylist named myList.
Basic Operations on ArrayList
In C#, we can perform different operations on arraylists. We will look at some commonly used arraylist operations in this tutorial:
- Add Elements
- Access Elements
- Change Elements
- Remove Elements
Let’s see how we can perform these operations in detail!
Add Elements in ArrayList
C# provides a method Add() using which we can add elements in ArrayList. For example,
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | using System; using System.Collections; class Program { public static void Main() { // create an ArrayList ArrayList student = new ArrayList(); // add elements to ArrayList student.Add("Tina"); student.Add(5); } } |
In the above example, we have created an ArrayList named student.
Then we added "Tina" and 5 to the ArrayList using the Add() method.
Other way to add Elements to ArrayList
Add Elements in an ArrayList using Object Initializer Syntax.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | using System; using System.Collections; class Program { public static void Main() { // create an ArrayList using var ArrayList myList = new ArrayList() { "Pizza", 24, "Pen" }; // iterate through items for (int i = 0; i < myList.Count; i++) { Console.WriteLine(myList[i]); } } } |
Add Elements in an ArrayList at specified index
To add an element to a specified index in ArrayList, we use the Insert() method. For example,
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | using System; using System.Collections; class Program { public static void Main() { // create an ArrayList ArrayList myList = new ArrayList(); myList.Add("Jimmy"); myList.Add("Blake"); myList.Add("Taylor"); Console.WriteLine("Before Inserting: " + myList[1]); // insert "Tim" at first index position myList.Insert(1, "Tim"); Console.WriteLine("After Inserting: " + myList[1]); } } |
In the above example, we have inserted "Tim" at the second index position using the Insert() method.
Access ArrayList Elements
We use indexes to access elements in ArrayList. The indexing starts from 0. For example,
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | using System; using System.Collections; class Program { public static void Main() { // create an ArrayList ArrayList schoolDetails = new ArrayList(); schoolDetails.Add("Mary's"); schoolDetails.Add("France"); schoolDetails.Add(23); // access the first element Console.WriteLine("First element: " + schoolDetails[0]); // access the second element Console.WriteLine("Second element: " + schoolDetails[1]); } } |
