Interpreter vs Visitor Pattern in C#: Key Differences Explained

A detailed comparison of the Interpreter and Visitor design patterns in C#, using arithmetic expression trees as a concrete example. The core distinction: the Interpreter embeds evaluation logic inside each node class, while the Visitor externalizes operations into separate classes. The Interpreter makes it easy to add new node types; the Visitor makes it easy to add new operations — a trade-off known as the 'expression problem.' Full C# code examples demonstrate both patterns evaluating (3+5)*2, and the article covers when to combine them, common mistakes, and a performance note.