Infinitely classified search-descendant tree, family tree

Unlimited classification search

$ Area = array (
Array ('id' => 1, 'name' => 'Beijing', 'parent' => 0 ),
Array ('id' => 2, 'name' => 'changping ', 'parent' => 1 ),
Array ('id' => 3, 'name' => 'haidian ', 'parent' => 2 ),
Array ('id' => 4, 'name' => 'Tianjin city ', 'parent' => 0 ),
Array ('id' => 5, 'name' => 'municipal authority ', 'parent' => 4 ),
Array ('id' => 6, 'name' => 'peaceful region', 'parent' => 5 ),
Array ('id' => 7, 'name' => 'hebei province ', 'parent' => 0 ),
Array ('id' => 8, 'name' => 'shijiazhuang city ', 'parent' => 7 ),
Array ('id' => 9, 'name' => 'Chang 'an District ', 'parent' => 8)
);

1: Find the subtree: Find the subnode under this node

/*** Find the subtree, subnode */function findson ($ arr, $ id = 0) {$ sons = array (); foreach ($ arr as $ value) {if ($ value ['parent'] ==$ id) {$ sons = $ value ;}} return $ sons ;} print_r (findson ($ area, 0 ));

2: Search for the child tree: find all the child nodes under the node and the child nodes under the child node, infinite search, until there is no child node, this uses recursive call to find.

/*** Find descendant tree */function subtree ($ arr, $ id, $ lev= 1) {$ subs = array (); foreach ($ arr as $ value) {if ($ value ['parent'] ==$ id) {$ value ['lev'] = $ lev; $ subs [] = $ value; $ subs = array_merge ($ subs, subtree ($ arr, $ value [id], $ annually + 1) ;}} return $ subs ;}

3: Search for the genealogy tree: find all the parent nodes of the node and continue to search for them through the parent node. The recursive call here is slightly different from the above, here, the array processing method is through the static keyword.

/*** Family tree */function familytree ($ arr, $ id) {static $ tree = array (); foreach ($ arr as $ value) {if ($ value ['id'] ==$ id) {$ tree [] = $ value; if ($ value ['parent']> 0) {familytree ($ arr, $ value ['parent']) ;}} return $ tree ;}

 

Infinitely classified search-descendant tree, family tree