【C++】关于头结点的一些理解

java - Head node in linked lists - Stack Overflow

 

These are called "dummy" header nodes, and they allow you to write general code that works for empty and non-empty lists.

Regularly, if you want to insert a Node at the end of your list, you need two cases. If head is null, indicating the list is empty, then you would set head to the new Node. If head is not null, then you follow the next pointers until you have the last Node, and set the next pointer to the new Node.

However, if you use a dummy header, head will never be null. It will be a Node with a null next pointer, which you can point to your new Node, just how you would if the list did contain nodes.