List

A List is similar to an array — it’s a collection of elements of the same type. But the difference is that its size isn’t fixed!
You can add or remove items from a list at any time —

Defining a List

To use a List, you need to include the following namespace:

using System.Collections.Generic;

Then, create a new list

List<int> numbers = new List<int>();

Adding Items to a List

numbers.Add(10);
numbers.Add(20);
numbers.Add(30);

Now, the numbers list contains [10, 20, 30].

Accessing List Elements

Just like arrays, you can access items in a list using their index:

Console.WriteLine(numbers[0]); // Output: 10
numbers[1] = 25;               // Change the value of the second element

Removing Items from a List

By Value:

numbers.Remove(25); // removes the number 25

By Index:

numbers.RemoveAt(0); // removes the first element

Counting Elements

You can find out how many items are currently in the list using Count:

Console.WriteLine(numbers.Count);

Looping Through a List

Using foreach

foreach (int n in numbers)
{
    Console.WriteLine(n);
}

Using for

for (int i = 0; i < numbers.Count; i++)
{
    Console.WriteLine(numbers[i]);
}