string oldSentence = "The quick brown fox jumps"; string newPhrase = "over the lazy dog."; string newSentence = oldSentence.Append(newPhrase); Console.WriteLine(newSentence);
StringBuilder sb = new StringBuilder("Hello "); sb.Append("world"); Console.WriteLine(sb.ToString());In this example, the `Append` method is used on a `StringBuilder` instance to add the string "world" to the existing text "Hello", resulting in the new string "Hello world". The package library for this method is also the System namespace. Overall, the System Append method is useful for appending new data to existing strings or string builders. It is part of the System namespace in C#, which is included in the .NET Framework libraries.