$arr=array(

array('id'=>'1','name'=>'吉林','parent'=>0),

array('id'=>'2','name'=>'北京','parent'=>0),

array('id'=>'3','name'=>'辽宁','parent'=>0),

array('id'=>'4','name'=>'吉林市','parent'=>1),

array('id'=>'5','name'=>'长春','parent'=>1),

array('id'=>'6','name'=>'海淀','parent'=>2),

array('id'=>'7','name'=>'大连','parent'=>3),

array('id'=>'8','name'=>'船营区','parent'=>4),

array('id'=>'9','name'=>'丰满区','parent'=>4)

);

//找子栏目

function findson($arr,$id=0){

$sons=array();

foreach($arr as $v){

if($v['parent']==$id){

$sons[]=$v;

}

}

return $sons;

}

//var_dump(findson($arr,$id=1));

//找子孙树

//用静态变量

function subtree($arr,$id,$lev=1){

static $subs=array(); //static 只初始化一次

foreach($arr as $v){

if($v['parent']==$id){

$v['lev']=$lev;

$subs[]=$v;

subtree($arr,$v['id'],$lev+1);

//不用静态变量

// $subs=array_merge($subs,subtree($arr,$v['id'],$lev+1));

}

}

return $subs;

}

/*

$tree=subtree($arr,$id=0,1);

foreach ($tree as $v){

echo str_repeat('  ',$v['lev']).$v['name']."
";

}

*/

/**

家谱树应用

面包屑导航

首页>手机类型>诺基亚>

**/

function familytree($area,$id){

static $tree=array();

foreach($area as $v){

if($v['id']==$id){

$tree[]=$v;

//判断要不要继续找父栏目

if($v['parent']>0){

familytree($area,$v['parent']);

//不用static

//array_merge($area,familytree($area,$v['parent']));

}

}

}

return $tree;

}

echo "

//print_r(familytree($arr,9));

/*用迭代找家谱树(推荐)*/

function familytree2($arr,$id){

$tree=array();

while($id!==0){

foreach($arr as $v){

if($v['id']==$id){

$tree[]=$v;

$id=$v['parent'];

break;

}

}

}

return $tree;

}

print_r(familytree2($arr,9));

?>