Some methods, such as Contains, IndexOf, LastIndexOf, and Remove, use an equality comparer for the list elements. The default equality comparer for type T is determined as follows: If type T implements IEquatable<T> then the default equality comparer is IEquatable;T>.Equals(T); otherwise the default equality comparer is object.Equals(Object).

Some methods, such as BinarySearch and Sort, use a comparer for the list elements. Some overloads of these methods take an explicit comparer as argument, while others use a default comparer. The default comparer for type T is determined as follows: If type T implements System.IComparable<T> then the default comparer is IComparable<T>.CompareTo(T); otherwise, if type T implements IComparable then the default comparer is IComparable.CompareTo(Object). If type T implements neither IComparable<T> nor IComparable then there is no default comparer; in this case a comparer or comparison delegate must be given explicitly.

The capacity of a List<T> is the number of elements the List<T> can hold. As elements are added to a List<T>, the capacity is automatically increased as required.. The capacity can be decreased by calling List<T>.TrimToSize or by setting the List<T>.Capacity property explicitly.

Indexes in this collection are zero-based.

List<T> accepts null as a valid value for reference types and allows duplicate elements.

This type contains a member that is a nested type, called Enumerator. Although Enumerator is a member of this type, Enumerator is not described here; instead, it is described in its own entry, List<T>.Enumerator.