Difference between ArrayList and List in C#.Net and VB.Net

By: Suresh Dasari Aug 10, 2016

Introduction:

Here I will explain difference between arraylist and list in c#, vb.net with example or arraylist vs generic list in asp.net using c#, vb.net with example or difference between generic list and arraylist collection in c#, vb.net with example. In c# or vb.net we use arraylist and generic lists to store any type of data in a collection format.

Description:

In previous posts I explained difference between char varchar nvarchar in sql, difference between website and web application in asp.net, difference between bit tinyint smallint int and bigint datatypes in sql server, difference between appsettings and connectionstrings in web.config, difference between ref and out in c#, vb.net with example and many articles related to interview questions, asp.net, c#.net. Now I will explain difference between arraylist and generic list in c#, vb.net with example.

ArrayList

Arraylist is used to store any type of data there is no restriction that mean we can store integer or string or any object based on our requirements. If we want to use ArrayList in our applications we need to add System.Collections namespace and ArrayList was introduced in .NET 2.0 framework.

C# Code

using System.Collections;

ArrayList arylist = new ArrayList();

arylist.Add("Suresh Dasari");

arylist.Add("aspdotnet-suresh.com");

arylist.Add(2046);

arylist.Add(DateTime.Now);

VB.NET Code

Imports System.Collections

Dim arylist As New ArrayList()

arylist.Add("Suresh Dasari")

arylist.Add("aspdotnet-suresh.com")

arylist.Add(2046)

arylist.Add(DateTime.Now)

If we want to get data from ArrayList we need to loop through that list as an object data type. In ArrayList the disadvantage is we don’t know what type of elements it will return while looping through an array object because we can store any type of elements.

Suppose if we want to get particular element from ArrayList we must be aware that what type of element that is otherwise it will throw error in case if we are assigning string element to integer datatype element.

C# Code

foreach(object obj in arylist){

}

VB.NET Code

For Each obj As Object In arylist

Generic lists are the type safe objects because it will store only specified datatype of elements. The Generic List declaration will be like List<T> here T means datatype i.e. either string, integer, etc.

If we want to use Generic List in our applications we need to add System.Collections.Generic namespace and Generic List was introduced in .NET 3.0 framework.

C# Code

using System.Collections.Generic;

List<int> lst = new List<int>();

lst.Add(232);

lst.Add(534);

lst.Add(2046);

VB.NET Code

Imports System.Collections.Generic

Dim lst As New List(Of Integer)()

lst.Add(232)

lst.Add(534)

lst.Add(2046)

If we want to get data from Generic List we can loop through that list with same object datatype whatever we defined while declaring Generic List. So to access elements from Generic List we won’t get any problem because we already aware that what type of elements our List contains.

C# Code

foreach (int num in lst)

{

}

VB.NET Code