CSharp Topic

Dot Net Basic
ArrayList class:-
Array List:-
  • It represents ordered collection of an object that can be indexed individually.
  • It is basically an alternative to an array. However unlike array you can add and remove items from a list at a specified position using an index and the array resizes itself automatically.
  • It also allows dynamic memory allocation, add, search and sort items in the list.


Methods and Properties of ArrayList class:-

Methods of ArrayList class:-

Sr.No. Methods
1 public virtual int Add(object value);

Adds an object to the end of the ArrayList.
2 public virtual void AddRange(ICollection c);

Adds the elements of an ICollection to the end of the ArrayList.
3 public virtual void Clear();

Removes all elements from the ArrayList.
4 public virtual bool Contains(object item);

Determines whether an element is in the ArrayList.
5 public virtual ArrayList GetRange(int index, int count);

Returns an ArrayList which represents a subset of the elements in the source ArrayList.
6 public virtual int IndexOf(object);

Returns the zero-based index of the first occurrence of a value in the ArrayList or in a portion of it.
7 public virtual void Insert(int index, object value);

Inserts an element into the ArrayList at the specified index.
8 public virtual void InsertRange(int index, ICollection c);

Inserts the elements of a collection into the ArrayList at the specified index.
9 public virtual void Remove(object obj);

Removes the first occurrence of a specific object from the ArrayList.
10 public virtual void RemoveAt(int index);

Removes the element at the specified index of the ArrayList.
11 public virtual void RemoveRange(int index, int count);

Removes a range of elements from the ArrayList.
12 public virtual void Reverse();

Reverses the order of the elements in the ArrayList.
13 public virtual void SetRange(int index, ICollection c);

Copies the elements of a collection over a range of elements in the ArrayList.
14 public virtual void Sort();

Sorts the elements in the ArrayList.
15 public virtual void TrimToSize();

Sets the capacity to the actual number of elements in the ArrayList.


Properties of ArrayList class:-

Property Description
Capacity Gets or sets the number of elements that the ArrayList can contain.
Count Gets the number of elements actually contained in the ArrayList.
IsFixedSize Gets a value indicating whether the ArrayList has a fixed size.
IsReadOnly Gets a value indicating whether the ArrayList is read-only.
Item Gets or sets the element at the specified index.


Example of ArrayList Class:- 

  
using System;
using System.Collections;
class ArrayListDemo
{
    public ArrayListDemo()
    {
        Console.WriteLine("This is array list demo by Santosh Kumar Singh::");
    }
    public void Show()
    {
        ArrayList al = new ArrayList();

        Console.WriteLine("\nAddition of some numbers:");
        al.Add(1001);
        al.Add(2003);
        al.Add(3300);
        al.Add(3033);
        al.Add(1002);
        al.Add(2300);
        al.Add(9036);

        Console.WriteLine("\nCapacity: {0} ", al.Capacity);
        Console.WriteLine("\nCount: {0}", al.Count);

        Console.Write("\nContent: ");
        foreach (int i in al)
        {
            Console.Write(i + " ");
        }

        Console.WriteLine();
        Console.Write("\nSorted Content: ");
        al.Sort();
        foreach (int i in al)
        {
            Console.Write(i + " ");
        }
        Console.WriteLine();
        Console.ReadKey();
    }
}

class Test
{
    static void Main(string[] args)
    {
        ArrayListDemo objArrayListDemo = new ArrayListDemo();
        objArrayListDemo.Show();
        Console.ReadLine();
    }
}