In visual basic, Arraylist is useful to store elements of different data types and the size of ArrayList can grow or shrink dynamically based on the need of our application like adding or removing elements from ArrayList.
In visual basic, array lists are same as arrays but the only difference is arrays are used to store a fixed number of same data type elements.
In visual basic, ArrayList is a non-generic type of collection and it is provided by System.Collections namespace.
As discussed, the collection is a class so to define an ArrayList, we must need to declare an instance of the ArrayList class before we perform any operations like add, delete, etc. like as shown below.
Dim arrlist As ArrayList = New ArrayList()
If you observe the above arraylist declaration, we created a new arraylist (arrList) with an instance of arraylist class without specifying any size.
The following are the some of commonly used properties of an arraylist in visual basic programming language.
| Property | Description |
|---|---|
| Capacity | It is used to get or set the number of elements an arraylist can contain. |
| Count | It is used to get the number of elements in arraylist. |
| IsFixedSize | It is used to get a value to indicate that the arraylist has fixed size or not. |
| IsReadOnly | It is used to get a value to indicate that the arraylist is readonly or not. |
| Item | It is used get or set an element at the specified index. |
| IsSynchronized | It is used to get a value to inidicate that an access to arraylist is synchronized (thread safe) or not. |
Following are the some of commonly used methods of an arraylist to add, search, insert, delete or sort an elements of arraylist in visual basic programming language.
| Method | Description |
|---|---|
| Add | It is used to add an element at the end of arraylist. |
| AddRange | It is used to add all the elements of specified collection at the end of arraylist. |
| Clear | It will remove all the elements in arraylist. |
| Clone | It will create a shallow copy of arraylist. |
| Contains | It is used determine whether the specified element exists in arraylist or not. |
| CopyTo | It is used to copy all the elements of an arraylist into another compatible array. |
| GetRange | It is used to return a specified range of arraylist elements starting from the specified index. |
| IndexOf | It is used to search for a specified element and return a zero-based index if found otherwise return -1 if no element found. |
| Insert | It is used to insert an element in arraylist at the specified index. |
| InsertRange | It is used to insert all the elements of specified collection into arraylist starting from the specified index. |
| Remove | It is used to remove a first occurence of specified element from the arraylist. |
| RemoveAt | It is used to remove an element from arraylist based on the specified index position. |
| RemoveRange | It is used to remove a range of elements from arraylist. |
| Reverse | It reverse the order of arraylist elements. |
| Sort | It sorts the elements in an arraylist. |
| ToArray | It copies all the elements of an arraylist to new array object. |
Following is the example of using an arraylist in visual basic programming language.
Module Module1
Sub Main(ByVal args As String())
Dim arrlist As ArrayList = New ArrayList()
arrlist.Add("Welcome")
arrlist.Add(100)
arrlist.Add(20.5)
arrlist.Add("Tutlane")
Console.WriteLine("ArrayList Count: " & arrlist.Count)
Console.WriteLine("ArrayList Capacity: " & arrlist.Capacity)
Console.WriteLine("*********ArrayList Elements********")
For Each item In arrlist
Console.WriteLine(item)
Next
Console.ReadLine()
End Sub
End Module
If you observe the above example, we are able to define a new arraylist (arrlist) collection. Here, we are binding a different data type values to newly created arraylist (arrlist) by using Add method and with Count & Capacity properties we are able to access the number of elements in an arraylist.
When we execute the above visual basic program, we will get the result like as shown below.
This is how we can use arraylist in visual basic to hold a group of different data type objects based on our requirements.
Following are the some of useful examples to work with arraylist in visual basic programming language.
In visual basic, by using the Add or AddRange method, we can add a different data type elements to an arraylist.
Following is the example of adding elements to arraylist using Add or AddRange methods in visual basic.
Module Module1
Sub Main(ByVal args As String())
' Creating arraylist
Dim arrlist As ArrayList = New ArrayList()
arrlist.Add("Welcome")
arrlist.Add(100)
arrlist.Add(20.5)
arrlist.Add("Tutlane")
' Creating arraylist
Dim arrlist2 As ArrayList = New ArrayList() From {10, "Hi"}
' Adding arrlist2 to arrlist
arrlist.AddRange(arrlist2)
Console.WriteLine("*********ArrayList Elements********")
For Each item In arrlist
Console.WriteLine(item)
Next
Console.ReadLine()
End Sub
End Module
If you observe the above example, we created multiple arraylists (arrlist, arrlist2) and adding an elements to the arraylists in different ways.
When we execute the above visual basic program, we will get the result like as shown below.
In visual basic, we have different ways to access arraylist elements i.e. either by using index positions or by iterating through an arraylist using For / For Each loops.
Following is the example of accessing the arraylist elements in different ways.
Module Module1
Sub Main(ByVal args As String())
' Creating ArrayList
Dim arrlist As ArrayList = New ArrayList()
arrlist.Add("Welcome")
arrlist.Add(100)
arrlist.Add(20.5F)
arrlist.Add("Tutlane")
' Accessing first element
Dim msg As String = CStr(arrlist(0))
' Accessing third element
Dim num As Single = CSng(arrlist(2))
Console.WriteLine("*********Access Elements with Index Position********")
Console.WriteLine("Element at 0: " & msg)
Console.WriteLine("Element at 2: " & num)
Console.WriteLine("*********Access Elements with For Loop********")
' For loop to access arraylist elements
For i As Integer = 0 To arrlist.Count - 1
Console.WriteLine(arrlist(i))
Next
Console.WriteLine("*********Access Elements with Foreach Loop********")
' For Each loop to access ArrayList elements
For Each item In arrlist
Console.WriteLine(item)
Next
Console.ReadLine()
End Sub
End Module
If you observe the above example, we are accessing the arraylist elements in different ways by using index positions, For and For Each loops based on our requirements.
When we execute the above visual basic program, we will get the result like as shown below.
In visual basic, we can insert elements into arraylist either by using Insert() or InsertRange() methods.
Following is the example of inserting elements into arraylist by using Insert and InsertRange methods in visual basic.
Module Module1
Sub Main(ByVal args As String())
' Creating arraylist
Dim arrlist As ArrayList = New ArrayList()
arrlist.Add("Welcome")
arrlist.Add(100)
arrlist.Add(20.5F)
arrlist.Add("Tutlane")
' Inserting elements into arraylist
arrlist.Insert(0, "Hi")
arrlist.Insert(1, 50)
Dim arrlist2 As ArrayList = New ArrayList() From {200, 300}
' Inserting arrlist2 into arrlist at position 2
arrlist.InsertRange(2, arrlist2)
Console.WriteLine("*********ArrayList Elements********")
For Each item In arrlist
Console.WriteLine(item)
Next
Console.ReadLine()
End Sub
End Module
If you observe the above example, we inserted elements into arraylist at different index positions (0, 1) by using Insert() method. Same way, by using InsertRange() method we are inserting all the element of newly created arraylist (arrlist2) into arrlist at index position 2.
When we execute the above visual basic program, we will get the result like as shown below.
In visual basic, we have different methods to remove elements from arraylist i.e. either by using Remove() or RemoveAt() or RemoveRange() methods.
Following is the example of deleting elements from arraylist in visual basic programming language.
Module Module1
Sub Main(ByVal args As String())
' Creating arraylist
Dim arrlist As ArrayList = New ArrayList()
arrlist.Add("Welcome")
arrlist.Add(100)
arrlist.Add(20.5F)
arrlist.Add("Tutlane")
arrlist.Add(200)
arrlist.Add(300)
arrlist.Add(400)
' Removing an element which is having a value 20.5f
arrlist.Remove(20.5F)
' Removing an element at index 0
arrlist.RemoveAt(0)
' Removing 2 elements starting from index 3
arrlist.RemoveRange(3, 2)
Console.WriteLine("*********ArrayList Elements********")
For Each item In arrlist
Console.WriteLine(item)
Next
Console.ReadLine()
End Sub
End Module
If you observe the above example, we used the Remove() method to delete a particular value of element from arraylist and used RemoveAt() method to delete an element at the specified index position.
Same way, we used RemoveRange() method to delete the specified number of elements from arraylist starting from the specified index position.
When we execute the above visual basic program, we will get the result like as shown below.
In case, if you want to remove all the elements from arraylist, then use Clear() method.
Same way, we can use different methods like Sort() method to sort an elements of arraylist and Reverse() method to reverse the order of arraylist elements.
By using Contains() method, we can check whether the specified element exists in arraylist or not. In case, if it exists it will return True otherwise False.
Following is the example of using Contains() method to check for an item exists in the arraylist or not in visual basic.
Module Module1
Sub Main(ByVal args As String())
' Creating arraylist
Dim arrlist As ArrayList = New ArrayList()
arrlist.Add("Welcome")
arrlist.Add(100)
arrlist.Add(20.5F)
arrlist.Add("Tutlane")
' Check for an item 100 exists in arraylist or not
Console.WriteLine("Item Exists: " & arrlist.Contains(100))
Console.ReadLine()
End Sub
End Module
If you observe the above example, we used Contains() method to check for an item (100) exists in the arraylist (arrlist) or not.
When we execute the above visual basic program, we will get the result like as shown below.
Following are the important points which we need to remember about arraylist in visual basic.
Following are the main difference between array and arraylist in visual basic programming language.