Collections of Game Objects - Learning C# by Programming Games - page 181

Fig. 12.2 An overview of the classes and interfaces related to collections

12.6 The Collection Interface

The library System.Collection.Generic contains more than only IList and List .Fig-
ure 12.2 shows an overview of the interfaces and classes that are part of the library.
There is a distinction between two kinds of interface:

• ISet , for data where the order does not matter;

• IList , for ordered data.

These are a number of methods (not all of them) that are specified in the interface
ICollection :

interface ICollection<E>
{

void Add (E x);
bool Remove (E x);
bool Contains (E x);
int Count { get ;}; // a read − only property

void Clear ();

}

All methods where an index is needed (in other words: methods requiring ordered
data), are in the sub-interface IList :

interface IList<E> : ICollection<E>
{

E this [ int n] { get ; set ;}; // this is the notation for defining indexing
int IndexOf (E x);
void Insert ( int n, E x);
void RemoveAt ( int n);

}