Lists

A List is another type of collection class. In contrast with an array, a List will dynamically increase its size as required.

(Some) Useful List Properties & Methods:

There are many properties and methods available in the List class: here are a few handy ones.

Properties

  • Capacity: lets us get or set the number of elements our List can contain.
  • Count: gets the number of elements currently in the List.
  • We can also access elements using square brackets, just like with an Array.

Methods

  • Add(): public method to add objects to the List.
  • Clear(): Removes all elements from the List.
  • Contains(): Determines whether an element is in the List.
  • CopyTo(): public method that copies a List to a 1-D array.
  • Insert(): Inserts an element into a List.
  • Sort(): sorts elements using the default comparer.

Creating Lists

This creates a list called dogList that holds references to Dog objects:

List<Dog> dogList = new List<Dog>();

We can even make a List containing elements of a built-in type. Here’s what that looks like, including adding, modifying, and removing elements:

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

marks.Add(50);      // add a new element with the value 50
marks.Add(75);      // add a new element with the value 75
marks.Add(100);     // add a new element with the value 100
marks[1] += 5;      // increase the value of the element at index 1
marks.RemoveAt(1);  // remove the element at index 1