<?php

/*
 * 找子欄目
 */

$area=array(
array('id'=>1,'name'=>'中國','parent'=>0),
array('id'=>2,'name'=>'廣東','parent'=>1),
array('id'=>3,'name'=>'深圳','parent'=>2),
array('id'=>4,'name'=>'湖南','parent'=>1),
array('id'=>5,'name'=>'長沙','parent'=>4)	
);

function findson($arr,$id=0) {
	  $son=array();
	foreach ($arr as $value) {
		if ($value['parent']==$id) {
			$son[]=$value;
		}
	}
	return $son;
}

/*
 * 找子孫樹
 * @param array 傳入的陣列
 * @param int  傳入的id
 */

function substree($arr,$id=0,$level=1) {
	   static $grandson=array();
	
	foreach ($arr as $value) {
		if ($value['parent']==$id) {
			$value['level']=$level;
			$grandson[]=$value;
			substree($arr,$value['id'],$level+1);
		}
	}
	  return $grandson;
}

//var_dump( findson($area,1));
echo  "</br>";
//var_dump(substree($area,2));

/*
 * 為了讓它顯示縮排效果
 */
$tt=substree($area,0,1);

   foreach ($tt as $value) {
   	 echo str_repeat('  ', $value["level"]).$value["name"]."</br>";
   }
   
?>