StringBuilder.Append Method (Object)

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.

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 Main()
   {
      Dog dog1 = new Dog("Yiska", "Alaskan Malamute");
      System.Text.StringBuilder sb = new System.Text.StringBuilder();     
      sb.Append(dog1).Append(", Breed: ").Append(dog1.Breed);  
      Console.WriteLine(sb);
   }
}
// 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 null, no changes are made to the StringBuilder object.

The capacity of this instance is adjusted as needed.

In the .NET Framework 4, when you instantiate the StringBuilder object by calling the StringBuilder 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.

.NET Framework

.NET Framework Client Profile

Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference