How to Append One StringBuilder to Another in C#

How can I effectively append one StringBuilder instance to another in C#?

StringBuilder sb1 = new StringBuilder("Hello, ");
StringBuilder sb2 = new StringBuilder("World!");
sb1.Append(sb2);
Console.WriteLine(sb1.ToString()); // Output: Hello, World!

Appending one StringBuilder instance to another in C# is straightforward. This operation includes incorporating all characters from the source StringBuilder into the destination one without creating a new instance, which is memory efficient.

StringBuilder sb1 = new StringBuilder("Hello, ");
StringBuilder sb2 = new StringBuilder("World!");
// Appending sb2 to sb1
sb1.Append(sb2);
Console.WriteLine(sb1.ToString()); // Output: Hello, World!

Causes

• Not understanding how StringBuilder handles memory allocation.
• Confusing StringBuilder's append methods with string concatenation.

Solutions

• Use the Append method to merge StringBuilder instances directly.
• Remember that the Append method modifies the original StringBuilder instance.

Mistake: Forgetting that Append modifies the original StringBuilder instead of returning a new one.

Solution: Always check the original StringBuilder after using Append to confirm it has been modified.

Mistake: Using the wrong overload of Append (e.g., appending a string rather than another StringBuilder).

Solution: Ensure you are using the appropriate Append method for the object type you are appending.