Use php reference to implement unlimited classification and output hierarchical arrays without recursion-PHP source code

Cleverly use php reference to implement unlimited classification, and output hierarchical arrays without recursive data table fields, IDs, and parentid.
Parent category parentid = 0, child category parentid = parent id.

Function getDataTree ($ rows, $ id = 'id', $ pid = 'parentid', $ child = 'child ', $ root = 0) {$ tree = array (); // tree if (is_array ($ rows) {$ array = array (); foreach ($ rows as $ key => $ item) {$ array [$ item [$ id] = & $ rows [$ key];} foreach ($ rows as $ key => $ item) {$ parentId = $ item [$ pid]; if ($ root = $ parentId) {$ tree [] = & $ rows [$ key];} else {if (isset ($ array [$ parentId]) {$ parent = & $ array [$ parentId]; $ parent [$ child] [] = & $ rows [$ key] ;}}} return $ tree ;}