Csharp/C Sharp/Collections Data Structure/ArrayList

Add array to ArrayList

<source lang="csharp">

using System; using System.Collections; using System.Collections.Generic; using System.Text; class Program {

   static void Main(string[] args) {
       ArrayList baseballTeams = new ArrayList();
       baseballTeams.Add("S");
       baseballTeams.Add("r");
       baseballTeams.Add("F");
       string[] myStringArray = new string[2];
       myStringArray[0] = "G";
       myStringArray[1] = "L";
       baseballTeams.AddRange(myStringArray);
       foreach (string item in baseballTeams) {
           Console.Write(item + "\n");
       }
   }

}

      </source>

Add items to ArrayList and use foreach loop to check

<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Text; class Program {

   static void Main(string[] args) {
       ArrayList baseballTeams = new ArrayList();
       baseballTeams.Add("s");
       baseballTeams.Add("r");
       baseballTeams.Add("F");
       foreach (string item in baseballTeams) {
           Console.Write(item + "\n");
       }
   }

}

      </source>

ArrayList Demo: hold class

<source lang="csharp"> /* Learning C# by Jesse Liberty Publisher: O"Reilly ISBN: 0596003765

• /

using System;
using System.Collections;
namespace ArrayListDemo
{
    // a class to hold in the array list
    class Employee
    {
        private int empID;
        public Employee(int empID)
        {
            this.empID = empID;
        }
        public override  string ToString()
        {
            return empID.ToString();
        }
        public int EmpID
        {
            get { return empID; }
            set { empID = value; }
        }
    }
    public class ArrayListDemoTester
    {
        public void Run()
        {
            ArrayList empArray = new ArrayList();
            ArrayList intArray = new ArrayList();
            // populate the arraylists
            for (int i = 0;i<5;i++)
            {
                empArray.Add(new Employee(i+100));
                intArray.Add(i*5);
            }
            // print each member of the array
            foreach (int i in intArray)
            {
                Console.Write("{0} ", i.ToString());
            }
            Console.WriteLine("\n");
            // print each employee
            foreach(Employee e in empArray)
            {
                Console.Write("{0} ", e.ToString());
            }
            Console.WriteLine("\n");
            Console.WriteLine("empArray.Capacity: {0}",
                empArray.Capacity);
        }
        [STAThread]
        static void Main()
        {
            ArrayListDemoTester t = new ArrayListDemoTester();
            t.Run();
        }
    }
}
          
      </source>

Binary Search an ArrayList

<source lang="csharp"> using System; using System.Collections; class Album : IComparable, ICloneable {

   private string _Title;
   private string _Artist;
   public Album(string artist, string title) {
       _Artist = artist;
       _Title = title;
   }
   public string Title {
       get {
           return _Title;
       }
       set {
           _Title = value;
       }
   }
   public string Artist {
       get {
           return _Artist;
       }
       set {
           _Artist = value;
       }
   }
   public override string ToString() {
       return _Artist + ",\t" + _Title;
   }
   public int CompareTo(object o) {
       Album other = o as Album;
       if (other == null)
           throw new ArgumentException();
       if (_Artist != other._Artist)
           return _Artist.rupareTo(other._Artist);
       else
           return _Title.rupareTo(other._Title);
   }
   public object Clone() {
       return new Album(_Artist, _Title);
   }

} class TitleComparer : IComparer {

   public int Compare(object l, object r) {
       Album left = l as Album;
       Album right = r as Album;
       if ((left == null) || (right == null))
           throw new ArgumentException();
       if (left.Title != right.Title)
           return left.Title.rupareTo(right.Title);
       else
           return left.Artist.rupareTo(right.Artist);
   }

} class Class1 {

   static void Main(string[] args) {
       ArrayList arr = new ArrayList();
       arr.Add(new Album("G", "A"));
       arr.Add(new Album("B", "G"));
       arr.Add(new Album("S", "A"));
       arr.Sort();
  
       try {
           foreach (Album a in arr) {
               Console.WriteLine(a);
           }
       } catch (System.InvalidCastException e) {
       }
       arr.Sort(new TitleComparer());
       foreach (Album a in arr) {
           Console.WriteLine(a);
       }
       Album l = new Album("L", "G");
       arr.Sort();
       int index = arr.BinarySearch(l);
       Console.WriteLine(index.ToString());
       arr.Sort(new TitleComparer());
       index = arr.BinarySearch(l, new TitleComparer());
       Console.WriteLine(index.ToString());
   }

}

      </source>

Check InvalidCastException when using foreach loop with ArrayList

<source lang="csharp"> using System; using System.Collections; class Album : IComparable, ICloneable {

   private string _Title;
   private string _Artist;
   public Album(string artist, string title) {
       _Artist = artist;
       _Title = title;
   }
   public string Title {
       get {
           return _Title;
       }
       set {
           _Title = value;
       }
   }
   public string Artist {
       get {
           return _Artist;
       }
       set {
           _Artist = value;
       }
   }
   public override string ToString() {
       return _Artist + ",\t" + _Title;
   }
   public int CompareTo(object o) {
       Album other = o as Album;
       if (other == null)
           throw new ArgumentException();
       if (_Artist != other._Artist)
           return _Artist.rupareTo(other._Artist);
       else
           return _Title.rupareTo(other._Title);
   }
   public object Clone() {
       return new Album(_Artist, _Title);
   }

} public class foo {

   public foo() {
       myString = "Test";
   }
   private string myString;

} class MainClass {

   static void Main(string[] args) {
       ArrayList arr = new ArrayList();
       arr.Add(new Album("G", "A"));
       arr.Add(new Album("B", "G"));
       arr.Add(new Album("S", "A"));
       arr.Sort();
       arr.Insert(0, new foo());
       try {
           foreach (Album a in arr) {
               Console.WriteLine(a);
           }
       } catch (System.InvalidCastException e) {
       }
   }

}

      </source>

Checks time needed for list operations using an ArrayList implementation

<source lang="csharp"> using System; using System.Drawing; using System.Collections; public class ArrayListTiming {

 public static void Main() {
   ArrayList arrayImp = new ArrayList();
   Point p = new Point(34, 156);
   int time1, time2;
   Object o;
   time1 = Environment.TickCount;
   for(int i = 0; i < 100000; i++)
      arrayImp.Add(p);
   time2 = Environment.TickCount;
   Console.WriteLine("Time for 100,000 adds: " + (time2 - time1));
   time1 = Environment.TickCount;
   for(int i = 0; i < 1000; i++)
      arrayImp.Insert(50, p);
   time2 = Environment.TickCount;
   Console.WriteLine("Time for 1,000 adds at position 50: " + (time2 - time1));
   time1 = Environment.TickCount;
   for(int i = 0; i < 10000000; i++)
      o = arrayImp[50];
   time2 = Environment.TickCount;
   Console.WriteLine ("Time for 10,000,000 gets at position 50: " + (time2 - time1));
 }

}

      </source>

Clone an ArrayList

<source lang="csharp">

using System; using System.Collections; public class Starter {

   public static void Main(string[] argv) {
       ArrayList al1 = new ArrayList();
       foreach (string arg in argv) {
           al1.Add(int.Parse(arg));
       }
       al1.Sort();
       ArrayList al2 = (ArrayList)al1.Clone();
       for (int count = 0; count < al2.Count; ++count) {
           al2[count] = ((int)al2[count]) * 2;
       }
       foreach (int number in al2) {
           Console.WriteLine(number);
       }
   }

}

      </source>

Convert an ArrayList into an array

<source lang="csharp"> /* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852

• /

// Convert an ArrayList into an array.

using System; using System.Collections;

public class ArrayListToArray {

 public static void Main() { 
   ArrayList al = new ArrayList(); 
    
   // Add elements to the array list. 
   al.Add(1); 
   al.Add(2); 
   al.Add(3); 
   al.Add(4); 

   Console.Write("Contents: "); 
   foreach(int i in al) 
     Console.Write(i + " "); 
   Console.WriteLine(); 

   // Get the array. 
   int[] ia = (int[]) al.ToArray(typeof(int)); 
   int sum = 0; 

   // sum the array 
   for(int i=0; i<ia.Length; i++) 
     sum += ia[i]; 

   Console.WriteLine("Sum is: " + sum); 
 } 

}

      </source>

CopyTo, ToArray(), ToArray(typeof(String))

<source lang="csharp">

using System; using System.Collections;

   class MainClass
   {
       public static void Main()
       {
           ArrayList list = new ArrayList(5);
           list.Add("B");
           list.Add("G");
           list.Add("J");
           list.Add("S");
           list.Add("M");
           string[] array1 = new string[list.Count];
           list.CopyTo(array1, 0);

           object[] array2 = list.ToArray();
           string[] array3 = (string[])list.ToArray(typeof(String));
           
           foreach (string s in array1)
           {
               Console.WriteLine(s);
           }
           foreach (string s in array2)
           {
               Console.WriteLine(s);
           }
           foreach (string s in array3)
           {
               Console.WriteLine(s);
           }
        }
   }
</source>

Demonstrate ArrayList

<source lang="csharp"> /* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852

• /

// Demonstrate ArrayList.

using System; using System.Collections;

public class ArrayListDemo {

 public static void Main() { 
   // create an array list 
   ArrayList al = new ArrayList(); 
    
   Console.WriteLine("Initial capacity: " + 
                      al.Capacity); 
   Console.WriteLine("Initial number of elements: " + 
                      al.Count); 

   Console.WriteLine(); 

   Console.WriteLine("Adding 6 elements"); 
   // Add elements to the array list 
   al.Add("C"); 
   al.Add("A"); 
   al.Add("E"); 
   al.Add("B"); 
   al.Add("D"); 
   al.Add("F"); 

   Console.WriteLine("Current capacity: " + 
                      al.Capacity); 
   Console.WriteLine("Number of elements: " + 
                      al.Count); 

   // Display the array list using array indexing. 
   Console.Write("Current contents: "); 
   for(int i=0; i < al.Count; i++) 
     Console.Write(al[i] + " "); 
   Console.WriteLine("\n"); 

   Console.WriteLine("Removing 2 elements"); 
   // Remove elements from the array list. 
   al.Remove("F"); 
   al.Remove("A"); 

   Console.WriteLine("Current capacity: " + 
                      al.Capacity); 
   Console.WriteLine("Number of elements: " + 
                      al.Count); 

   // Use foreach loop to display the list. 
   Console.Write("Contents: "); 
   foreach(char c in al) 
     Console.Write(c + " "); 
   Console.WriteLine("\n"); 

   Console.WriteLine("Adding 20 more elements"); 
   // Add enough elements to force al to grow. 
   for(int i=0; i < 20; i++) 
     al.Add((char)("a" + i)); 
   Console.WriteLine("Current capacity: " + 
                      al.Capacity); 
   Console.WriteLine("Number of elements after adding 20: " + 
                      al.Count); 
   Console.Write("Contents: "); 
   foreach(char c in al) 
     Console.Write(c + " "); 
   Console.WriteLine("\n"); 

   // Change contents using array indexing. 
   Console.WriteLine("Change first three elements"); 
   al[0] = "X"; 
   al[1] = "Y"; 
   al[2] = "Z"; 
   Console.Write("Contents: "); 
   foreach(char c in al) 
     Console.Write(c + " "); 
   Console.WriteLine(); 
 } 

}

      </source>

illustrates the use of an ArrayList that contains objects of the Car class

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

/*

 Example11_3.cs illustrates the use of an ArrayList that contains
 objects of the Car class

• /

using System; using System.Collections;

// declare the Car class class Car : IComparable {

 // declare the fields
 public string model;
 public int yearBuilt;
 // define the constructor
 public Car(string model, int yearBuilt)
 {
   this.model = model;
   this.yearBuilt = yearBuilt;
 }
 // override the ToString() method
 public override string ToString()
 {
   return "model is " + model + ", yearBuilt is " + yearBuilt;
 }
 // implement the Compare() method of IComparer
 public int Compare(object lhs, object rhs)
 {
   Car lhsCar = (Car) lhs;
   Car rhsCar = (Car) rhs;
   if (lhsCar.yearBuilt < rhsCar.yearBuilt)
   {
     return -1;
   }
   else if (lhsCar.yearBuilt > rhsCar.yearBuilt)
   {
     return 1;
   }
   else
   {
     return 0;
   }
 }
 // implement the CompareTo() method of IComparable
 public int CompareTo(object rhs)
 {
   return Compare(this, rhs);
 }
 // alternative CompareTo() method that simply calls the
 // CompareTo() method that comes with the int type
 // (currently commented out)
 /* public int CompareTo(object rhs)
 {
   Car rhsCar = (Car) rhs;
   return this.yearBuilt.rupareTo(rhsCar.yearBuilt);
 }*/

}

public class Example11_3 {

 // the DisplayArrayList() method displays the elements in the
 // supplied ArrayList
 public static void DisplayArrayList(
   string arrayListName, ArrayList myArrayList
 )
 {
   for (int counter = 0; counter < myArrayList.Count; counter++)
   {
     Console.WriteLine(arrayListName + "[" + counter + "] = " +
       myArrayList[counter]);
   }
 }
 public static void Main()
 {
   // create an ArrayList object
   ArrayList myArrayList = new ArrayList();
   // add four Car objects to myArrayList using the Add() method
   Console.WriteLine("Adding four Car objects to myArrayList");
   Car myMR2 = new Car("MR2", 2001);
   Car myBoxster = new Car("Boxster", 2001);
   Car myCorvette = new Car("Corvette", 1999);
   Car myThunderbird = new Car("Thunderbird", 1979);
   myArrayList.Add(myMR2);
   myArrayList.Add(myBoxster);
   myArrayList.Add(myCorvette);
   myArrayList.Add(myThunderbird);
   DisplayArrayList("myArrayList", myArrayList);
   // use the Contains() method to determine if myBoxster
   // is in the ArrayList; if it is, then use the IndexOf()
   // method to display the index
   if (myArrayList.Contains(myBoxster))
   {
     Console.WriteLine("myArrayList does contain myBoxster");
     int index = myArrayList.IndexOf(myBoxster);
     Console.WriteLine("myBoxster occurs at index " + index);
   }
   // remove myBoxster from myArrayList
   Console.WriteLine("Removing myBoxster from myArrayList");
   myArrayList.Remove(myBoxster);
   DisplayArrayList("myArrayList", myArrayList);
   // use the Sort() method to sort myArrayList
   Console.WriteLine("Using the Sort() method to sort myArrayList");
   myArrayList.Sort();
   DisplayArrayList("myArrayList", myArrayList);
   // use the BinarySearch() method to search myArrayList for
   // myCorvette
   Console.WriteLine("Using the BinarySearch() method to search myArrayList\n" +
     " for myCorvette");
   int index2 = myArrayList.BinarySearch(myCorvette);
   Console.WriteLine("Found myCorvette at index " + index2);
   // use the GetRange() method to get a range of elements
   // from myArrayList
   Console.WriteLine("Using the GetRange() method to get two\n" +
     " elements from myArrayList, starting at index 1");
   ArrayList anotherArrayList = myArrayList.GetRange(1, 2);
   DisplayArrayList("anotherArrayList", anotherArrayList);
   // get an enumerator using the GetEnumerator() method
   // and use it to read the elements in myArrayList
   Console.WriteLine("Using the GetEnumerator() method to get an enumerator");
   IEnumerator myEnumerator = myArrayList.GetEnumerator();
   while (myEnumerator.MoveNext())
   {
     Console.WriteLine("myEnumerator.Current = " + myEnumerator.Current);
   }
   // use the Reset() method and access the first row again using MoveNext()
   Console.WriteLine("Using the Reset() method and accessing\n" +
     " the first row again using MoveNext()");
   myEnumerator.Reset();
   myEnumerator.MoveNext();
   Console.WriteLine("myEnumerator.Current = " + myEnumerator.Current);
   // Use a foreach statement to read the contents of myArrayList
   Console.WriteLine("Using a foreach statement to read the contents of myArrayList");
   foreach (Car myCar in myArrayList)
   {
     System.Console.WriteLine("myCar = " + myCar);
   }
 }

}

      </source>

illustrates the use of ArrayList properties and methods

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

/*

 Example11_2.cs illustrates the use of ArrayList properties
 and methods

• /

using System; using System.Collections; public class Example11_2 {

 // the DisplayArrayList() method displays the elements in the
 // ArrayList that is supplied as a parameter
 public static void DisplayArrayList(
   string arrayListName, ArrayList myArrayList
 )
 {
   for (int counter = 0; counter < myArrayList.Count; counter++)
   {
     Console.WriteLine(arrayListName + "[" + counter + "] = " +
       myArrayList[counter]);
   }
 }
 public static void Main()
 {
   // create an ArrayList object
   ArrayList myArrayList = new ArrayList();
   // set and display the Capacity property
   myArrayList.Capacity = 10;
   Console.WriteLine("myArrayList.Capacity = " +
     myArrayList.Capacity);
   // display the IsFixedSize and IsReadOnly properties
   Console.WriteLine("myArrayList.IsFixedSize = " +
     myArrayList.IsFixedSize);
   Console.WriteLine("myArrayList.IsReadOnly = " +
     myArrayList.IsReadOnly);
   // add eight string elements to myArrayList using the Add(),
   // Insert(), AddRange(), and InsertRange() methods
   Console.WriteLine("Adding eight string elements to myArrayList");
   myArrayList.Add("This");
   myArrayList.Insert(1, "is");
   string[] myStringArray = {"a", "test"};
   myArrayList.AddRange(myStringArray);
   string[] anotherStringArray = {"Here"s", "some", "more", "text"};
   myArrayList.InsertRange(myArrayList.Count, anotherStringArray);
   // display the elements in myArrayList using the
   // DisplayArrayList() method defined earlier
   DisplayArrayList("myArrayList", myArrayList);
   // use the SetRange() method to copy the elements from
   // anotherStringArray to myArrayList, starting at index 0
   Console.WriteLine("Using the SetRange() method to copy the\n" +
     "elements from anotherStringArray to myArrayList,\n" +
     "starting at index 0");
   myArrayList.SetRange(0, anotherStringArray);
   DisplayArrayList("myArrayList", myArrayList);
   // use the Contains() method to determine if the string "text"
   // is in the ArrayList; if it is, then use the IndexOf() and
   // LastIndexOf() methods to display the first and last occurrence
   if (myArrayList.Contains("text"))
   {
     int index = myArrayList.IndexOf("text");
     Console.WriteLine("myArrayList does contain the word "text"");
     Console.WriteLine(""text" first occurs at index " + index);
     index = myArrayList.LastIndexOf("text");
     Console.WriteLine(""text" last occurs at index " + index);
   }
   // remove element 0, first "text" element, and two
   // elements starting at index 3
   Console.WriteLine("Removing elements from myArrayList");
   myArrayList.RemoveAt(0);
   myArrayList.Remove("text");
   myArrayList.RemoveRange(3, 2);
   DisplayArrayList("myArrayList", myArrayList);
   // use the Sort() method to sort myArrayList
   Console.WriteLine("Using the Sort() method to sort myArrayList");
   myArrayList.Sort();
   DisplayArrayList("myArrayList", myArrayList);
   // use the BinarySearch() method to search myArrayList
   Console.WriteLine("Using the BinarySearch() method to search myArrayList");
   int index2 = myArrayList.BinarySearch("some");
   Console.WriteLine("Found "some" at index " + index2);
   // use the Reverse() method to reverse myArrayList
   Console.WriteLine("Using the Reverse() method");
   myArrayList.Reverse();
   DisplayArrayList("myArrayList", myArrayList);
   // use the TrimToSize() method to reduce the capacity of
   // myArrayList to the actual number of elements in myArrayList
   Console.WriteLine("Using the TrimToSize() method to reduce the\n" +
     "capacity of myArrayList");
   myArrayList.TrimToSize();
   Console.WriteLine("myArrayList.Capacity = " +
     myArrayList.Capacity);
   // use the GetRange() method to get a range of elements
   // from myArrayList
   Console.WriteLine("Using the GetRange() method to get two\n" +
     "elements from myArrayList, starting at index 1");
   ArrayList anotherArrayList = myArrayList.GetRange(1, 2);
   DisplayArrayList("anotherArrayList", anotherArrayList);
   // get an enumerator using the GetEnumerator() method
   // and use it to read the elements in myArrayList
   Console.WriteLine("Using the GetEnumerator() method to get an enumerator");
   IEnumerator myEnumerator = myArrayList.GetEnumerator();
   while (myEnumerator.MoveNext())
   {
     Console.WriteLine("myEnumerator.Current = " + myEnumerator.Current);
   }
   // use the Reset() method and access the first row again using MoveNext()
   Console.WriteLine("Using the Reset() method and accessing\n" +
     " the first row again using MoveNext()");
   myEnumerator.Reset();
   myEnumerator.MoveNext();
   Console.WriteLine("myEnumerator.Current = " + myEnumerator.Current);
   // Use a foreach statement to read the contents of myArrayList
   Console.WriteLine("Using a foreach statement to read the contents of myArrayList");
   foreach (string myString in myArrayList)
   {
     System.Console.WriteLine("myString = " + myString);
   }
 }

}

      </source>

illustrates the use of ArrayLists 2

<source lang="csharp"> /* Mastering Visual C# .NET by Jason Price, Mike Gunderloy Publisher: Sybex; ISBN: 0782129110

• /

/*

 Example11_1.cs illustrates the use of ArrayLists

• /

using System; using System.Collections; public class Example11_1 {

 // the DisplayArrayList() method displays the elements in the
 // ArrayList that is supplied as a parameter
 public static void DisplayArrayList(
   string arrayListName, ArrayList myArrayList
 )
 {
   for (int counter = 0; counter < myArrayList.Count; counter++)
   {
     Console.WriteLine(arrayListName + "[" + counter + "] = " +
       myArrayList[counter]);
   }
 }
 public static void Main()
 {
   // create an ArrayList object
   ArrayList myArrayList = new ArrayList();
   // display the Capacity property
   Console.WriteLine("myArrayList.Capacity = " +
     myArrayList.Capacity);
   // add four strings to myArrayList using the Add() method
   myArrayList.Add("This");
   myArrayList.Add("is");
   myArrayList.Add("a");
   myArrayList.Add("test");
   // display the contents of myArrayList using DisplayArrayList()
   DisplayArrayList("myArrayList", myArrayList);
   // create another ArrayList, passing myArrayList to the
   // constructor of the new ArrayList
   ArrayList anotherArrayList = new ArrayList(myArrayList);
   // display the contents of anotherArrayList
   DisplayArrayList("anotherArrayList", anotherArrayList);
 }

}

      </source>

Inserting into an ArrayList by index

<source lang="csharp">

using System; using System.Collections; class MainClass {

   public static void Main() {
       ArrayList al = new ArrayList(5);
       // Add three elements to the end of the array
       al.Add(10);
       al.Add(9);
       al.Add(8);
       // Now, insert three elements in the front of the array
       al.Insert(0, 1);
       al.Insert(0, 2);
       al.Insert(0, 3);
       // Finally, insert into some random spots
       al.Insert(2, 4);
       al.Insert(4, 5);
       al.Insert(6, 6);

       // Enumerate the array
       foreach (int i in al) {
           Console.WriteLine("Entry {0}", i);
       }
   }

}

      </source>

Remove range from ArrayList

<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Text; class Program {

   static void Main(string[] args) {
       ArrayList baseballTeams = new ArrayList();
       baseballTeams.Add("s");
       baseballTeams.Add("r");
       baseballTeams.Add("i");
       string[] myStringArray = new string[2];
       myStringArray[0] = "t";
       myStringArray[1] = "L";
       baseballTeams.AddRange(myStringArray);
       baseballTeams.RemoveRange(2, 2);
       foreach (string item in baseballTeams) {
           Console.Write(item + "\n");
       }
       Console.ReadLine();
   }

}

      </source>

Sort and search an ArrayList

<source lang="csharp"> /* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852

• /

// Sort and search an ArrayList.

using System; using System.Collections;

public class SortSearchDemo {

 public static void Main() { 
   // create an array list 
   ArrayList al = new ArrayList(); 
    
   // Add elements to the array list 
   al.Add(55); 
   al.Add(43); 
   al.Add(-4); 
   al.Add(88); 
   al.Add(3); 
   al.Add(19); 

   Console.Write("Original contents: "); 
   foreach(int i in al) 
     Console.Write(i + " "); 
   Console.WriteLine("\n"); 

   // Sort 
   al.Sort(); 

   // Use foreach loop to display the list. 
   Console.Write("Contents after sorting: "); 
   foreach(int i in al) 
     Console.Write(i + " "); 
   Console.WriteLine("\n"); 

   Console.WriteLine("Index of 43 is " + 
                     al.BinarySearch(43)); 
 } 

}

      </source>

Using foreach to loop through ArrayList and use Indexer of ArrayList

<source lang="csharp">

using System; using System.Collections; class CollectionsDemo {

   public static void Main(String[] args) {
       ArrayList PokerPlayers = new ArrayList(3);
       PokerPlayers.Add("J");
       PokerPlayers.Add("M");
       PokerPlayers.Add("A");
       PokerPlayers.Add("J");
       foreach (String Player in PokerPlayers) {
           Console.WriteLine(Player);
       }
       PokerPlayers[0] = "A";
       System.Console.WriteLine(PokerPlayers[0]);
   }

}

      </source>