Dynamic array in C#

Take a look at Generic Lists.

Expanding on Chris and Migol`s answer with a code sample.

Using an array

Student[] array = new Student[2];
array[0] = new Student("bob");
array[1] = new Student("joe");

Using a generic list. Under the hood the List<T> class uses an array for storage but does so in a fashion that allows it to grow effeciently.

List<Student> list = new List<Student>();
list.Add(new Student("bob"));
list.Add(new Student("joe"));
Student joe = list[1];

List<T> for strongly typed one, or ArrayList if you have .NET 1.1 or love to cast variables.

You can do this with dynamic objects:

var dynamicKeyValueArray = new[] { new {Key = "K1", Value = 10}, new {Key = "K2", Value = 5} };

foreach(var keyvalue in dynamicKeyValueArray)
{
    Console.Log(keyvalue.Key);
    Console.Log(keyvalue.Value);
}

you can use arraylist object from collections class

using System.Collections;

static void Main()
{
  ArrayList arr = new ArrayList();
}

when you want to add elements you can use

arr.Add();