StringBuilder.Append Method (Object)


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Appends the string representation of a specified object to this instance.

Namespace:   System.Text
Assembly:  mscorlib (in mscorlib.dll)

Public Function Append (
	value As Object
) As StringBuilder


Type: System.Object

The object to append.

Return Value

Type: System.Text.StringBuilder

A reference to this instance after the append operation has completed.

Exception Condition

Enlarging the value of this instance would exceed MaxCapacity.

The Append(Object) method modifies the existing instance of this class; it does not return a new class instance. Because of this, you can call a method or property on the existing reference and you do not have to assign the return value to a StringBuilder object, as the following example illustrates. It defines a Dog class, creates a Dog object, and makes three calls to the Append method to create a string that contains the dog's name and breed.

Public Class Dog
   Private dogBreed As String
   Private dogName As String

   Public Sub New(name As String, breed As String)
      Me.dogName = name
      Me.dogBreed = breed
   End Sub

   Public ReadOnly Property Breed As String
         Return Me.dogBreed
      End Get
   End Property

   Public ReadOnly Property Name As String
         Return Me.dogName
      End Get
   End Property

   Public Overrides Function ToString() As String
      Return Me.dogName
   End Function
End Class

Module Example
   Public Sub Main()
      Dim dog1 As New Dog("Yiska", "Alaskan Malamute")
      Dim sb As New System.Text.StringBuilder()     
      sb.Append(dog1).Append(", Breed: ").Append(dog1.Breed)  
   End Sub
End Module
' The example displays the following output:
'       Yiska, Breed: Alaskan Malamute

The Append(Object) method calls the Object.ToString method to get the string representation of value. If value is null, no changes are made to the StringBuilder object.

The capacity of this instance is adjusted as needed.

Notes to Callers:

In the.NET Framework 4 and the .NET Framework 4.5, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. This can occur particularly when you call the Append and AppendFormat methods to append small strings.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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