Two-dimensional arrays, collections

Collection: Define a collection, set Stone a class, in the System.Collections library, you need an index
ArrayList al = new ArrayList (); The collection is indexed as an array, and the index starts at 0 and adds the meaning of an int value.
int i= al. Add (3);//print out an int value returned by index 0, which is the index of the added data in the collection
int a= al. ADD (5);
int b= al. ADD (7);
Al. Insert (1,9);//Inserts an index of 1 inserts a 9 at 1 on this index, insert data 9. The data of the original position is indexed in turn by one
Al. Remove (7);//Reject data If there are two identical values remove the first one
Al. RemoveAt (1);//Remove Index
int cc = al. The number of count;//collection lengths
Console.Write (al[0]);//Read index
Console.Write (al[1]);
Console.Write (al[2]);
Console.Write (Al[3]);

Console.Write (i + "+ A +" "+ b);//There is only one entrance at the end,
Console.WriteLine (CC);
Console.ReadLine ();

The number of people with each person's score is stored in the collection and the loop reads

Two-dimensional arrays, collections