Web Application Development with PHP 4.0

Linked Lists

Linked lists, a special form of trees, are one of the most typical data structures to organize dynamic datasets. We're assuming that you already have an understanding of the structure, concept, and usage of linked lists, so we won't go deeply into their implementation here; we'd rather concentrate on the elemental do's and don'ts.

As described in the previous sections, PHP 3.0 creates copies of object instances rather than referring to them by using a pointer. This only enables a very limited, WORM-like use of linked lists: write once, read multiple. Linked lists can be created, but not modified. When you try to modify an element in the list, you lose the reference to all following elements in the list. Regrouping of elements is ...