C-Sharp | Java | Python | Swift | GO | WPF | Ruby | Scala | F# | JavaScript | SQL | PHP | Angular | HTML
Tip: You do not need to check to see if there is room before adding the element.
Tip 2: There will always be room except in extreme circumstances such as out-of-memory situations.
VB.NET program that uses Add, ArrayList
Module Module1
Sub Main()
' Create a new ArrayList.
' ... Then add three strings to it.
Dim list As New ArrayList
list.Add("One")
list.Add("Two")
list.Add("Three")
End Sub
End Module
Tip: The Example method here could be used with any ArrayList instance, with any elements in its internal storage.
VB.NET program that uses ArrayList with method
Module Module1
Sub Main()
' Create an ArrayList and add two elements to it.
Dim list As New ArrayList
list.Add(5)
list.Add(7)
' Use ArrayList as an argument to the method.
Example(list)
End Sub
''' <summary>
''' Receives ArrayList as argument.
''' </summary>
Private Sub Example(ByVal list As ArrayList)
Dim num As Integer
For Each num In list
Console.WriteLine(num)
Next
End Sub
End Module
Output
5
7
Argument: AddRange receives one argument—an ArrayList that contains elements you want to add.
Here: In this example, the two array lists are effectively concatenated. This is done with the AddRange Sub.
VB.NET program that uses AddRange method
Module Module1
Sub Main()
' Create an ArrayList and add two elements.
Dim list1 As New ArrayList
list1.Add(5)
list1.Add(7)
' Create a separate ArrayList.
Dim list2 As New ArrayList
list2.Add(10)
list2.Add(13)
' Add this ArrayList to the other one.
list1.AddRange(list2)
' Loop over the elements.
Dim num As Integer
For Each num In list1
Console.WriteLine(num)
Next
End Sub
End Module
Output
5
7
10
13
Count: This is a property. Count quickly returns the number of elements in the ArrayList.
PropertyClear: This example uses the Clear method. After you call the Clear method, the Count property will return zero elements.
VB.NET program that uses ArrayList and Count property
Module Module1
Sub Main()
' Add two elements to the ArrayList.
Dim list As New ArrayList
list.Add(9)
list.Add(10)
' Write the Count.
Console.WriteLine(list.Count)
' Clear the ArrayList.
list.Clear()
' Write the Count again.
Console.WriteLine(list.Count)
End Sub
End Module
Output
2
0
RemoveAt: We see how the RemoveAt method works. It receives an index argument, which corresponds to the element index you want to remove.
Insert: The Insert method receives two arguments: the position you want to insert at, and the object reference itself.
RemoveRange: Finally, RemoveRange receives the index you want to start removing at, and the number of elements you want to remove.
VB.NET program that uses Add, RemoveAt, Insert, RemoveRange
Module Module1
Sub Main()
' Create an ArrayList and add three strings to it.
Dim list As New ArrayList
list.Add("Dot")
list.Add("Net")
list.Add("Perls")
' Remove a string.
list.RemoveAt(1)
' Insert a string.
list.Insert(0, "Carrot")
' Remove a range.
list.RemoveRange(0, 2)
' Display.
Dim str As String
For Each str In list
Console.WriteLine(str)
Next
End Sub
End Module
Output
Perls
Operator: TryCast receives two arguments: the element we want to cast from the ArrayList, and the type to which we want to cast.
Warning: The TryCast operator will not throw exceptions, as it uses the tester-doer pattern.
TryCastVB.NET program that uses TryCast, ArrayList
Module Module1
Sub Main()
' Create a new ArrayList.
Dim list As New ArrayList
list.Add("man")
list.Add("woman")
list.Add("plant")
' Loop over the ArrayList with a For-loop.
Dim i As Integer
For i = 0 To list.Count - 1
' Cast to a string.
Dim str As String = TryCast(list.Item(i), String)
Console.WriteLine(str)
Next i
End Sub
End Module
Output
man
woman
plant
Then: Assign the result of the GetRange method call to a new ArrayList variable reference.
Note: GetRange receives the starting index from which you want to copy, and then the count of elements you want to get.
IntegerVB.NET program that uses ArrayList and GetRange
Module Module1
Sub Main()
' Create new ArrayList.
Dim list1 As New ArrayList
list1.Add("fish")
list1.Add("amphibian")
list1.Add("bird")
list1.Add("plant")
' Create a new ArrayList.
' ... Fill it with the range from the first one.
Dim list2 As New ArrayList
list2 = list1.GetRange(2, 2)
' Loop over the elements.
Dim str As String
For Each str In list2
Console.WriteLine(str)
Next
End Sub
End Module
Output
bird
plant