StringBuilder.Append Method (Object)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

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

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


Public Function Append ( _
    value As Object _
) As StringBuilder
public StringBuilder Append(
    Object value


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 its maximum capacity.


The Append 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 Demo(outputBlock As System.Windows.Controls.TextBlock)
      Dim dog1 As New Dog("Yiska", "Alaskan Malamute")
      Dim sb As New System.Text.StringBuilder()     
      sb.Append(dog1).Append(", Breed: ").Append(dog1.Breed)  
      outputBlock.Text += sb.ToString() + Environment.NewLine
   End Sub
End Module
' The example displays the following output:
'       Yiska, Breed: Alaskan Malamute
using System;

public class Dog
   private string dogBreed;
   private string dogName;

   public Dog(string name, string breed)
      this.dogName = name;
      this.dogBreed = breed;

   public string Breed {
      get { return this.dogBreed; }

   public string Name {
      get { return this.dogName; }

   public override string ToString()
      return this.dogName;

public class Example
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
      Dog dog1 = new Dog("Yiska", "Alaskan Malamute");
      System.Text.StringBuilder sb = new System.Text.StringBuilder();     
      sb.Append(dog1).Append(", Breed: ").Append(dog1.Breed);  
      outputBlock.Text += sb + Environment.NewLine;
// The example displays the following output:
//        Yiska, Breed: Alaskan Malamute

The Append method calls the Object..::.ToString method to get the string representation of value. If value is nullNothingnullptra null reference (Nothing in Visual Basic), no changes are made to the StringBuilder object.

The capacity of this instance is adjusted as needed.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0


Windows Phone

See Also


StringBuilder Class

Append Overload

System.Text Namespace