關於「Nil computer science」標籤，搜尋引擎有相關的訊息討論：

The concept of `Nil` in C++ - Stack Overflowstackoverflow.com › questions › the-concept-of-nil-in-cWhat is the purpose of using NIL for representing null nodes?cs.stackexchange.com › questions › what-is-the-purpose-of...What is nil? | Definition from TechTargetwhatis.techtarget