2014-12-18 Collection

First, define a new array class

Class Arraylistjihe
    {
        static void Main ( string[] args
        {
             ArrayList arr = new ArrayList ();
            arr. ADD (3);    
            arr. ADD ("Hello");
            // Generate a 0-based index by adding an element's order, reading the data through an index
             Console.WriteLine (arr[0]);
            Console.WriteLine (arr[2]);
       }
   }

ArrayList must refer to using System.Collections;

Arr. Insert (1,17) //17 This number is inserted at the position of the collection 1

Int[] Shuzu=new int[3]{6,7,8};

Arr.   Insertrange (1,shuzu); //split coefficient group, insert array to 1 position

Arr.  AddRange (Shuzu); //detach the coefficient group, append the array to the position following the collection

Show all content in a collection

foreach (Object o in arr)
{
Console.WriteLine (O.tostring ());
}

Adding an array entity
Arr. ADD (Shuzu);
int [] newshu= (int[]arr[3]);
foreach (int a in Newshu)
{
Console.WriteLine (a);
}

removing data
Arr.  Remove ("Hello"); //Remove the Hello from the first position
Arr.   RemoveAt (3); //Remove data at the specified location

Sorting functions for collections
ArrayList arr = new ArrayList ();
for (int i = 0; i < 5; i++)
{
Arr. ADD (int. Parse (Console.ReadLine ()));
}
Arr.  Sort (); //Ascending sort
Arr.  Reverse (); //Flip the collection

foreach (int a in arr)
{
Console.WriteLine (a);
}

Console.WriteLine (arr.  Count); //Returns the number of elements in the collection
Console.WriteLine (arr. IndexOf (14)); //Returns the position of the first 14 in a collection
Console.WriteLine (arr. LastIndexOf (14)); //Returns the position of the last 14 in the collection

2014-12-18 Collection