php实现无限级分类

摘要: php实现无限级分类

1，数组

$area

=

array

(

array

(

'id'

=>1,

'name'

=>

'安徽'

,

'parent'

=>0),

array

(

'id'

=>2,

'name'

=>

'海淀'

,

'parent'

=>7),

array

(

'id'

=>3,

'name'

=>

'濉溪县'

,

'parent'

=>5),

array

(

'id'

=>4,

'name'

=>

'昌平'

,

'parent'

=>7),

array

(

'id'

=>5,

'name'

=>

'淮北'

,

'parent'

=>1),

array

(

'id'

=>6,

'name'

=>

'朝阳'

,

'parent'

=>7),

array

(

'id'

=>7,

'name'

=>

'北京'

,

'parent'

=>0),

array

(

'id'

=>8,

'name'

=>

'上地'

,

'parent'

=>2)

);

2，递归，查找子孙树

function

subtree(

$arr

,

$id

=0,

$lev

=1) {

$subs

=

array

();

// 子孙数组

foreach

(

$arr

as

$v

) {

if

(

$v

[

'parent'

] ==

$id

) {

$v

[

'lev'

] =

$lev

;

$subs

[] =

$v

;

// 举例说找到array('id'=>1,'name'=>'安徽','parent'=>0),

$subs

=

array_merge

(

$subs

,subtree(

$arr

,

$v

[

'id'

],

$lev

+1));

}

}

return

$subs

;

}

$tree

=subtree(

$area

,0,1);

foreach

(

$tree

as

$v

) {

echo

str_repeat

(

'  '

,

$v

[

'lev'

]),

$v

[

'name'

],

'<br />'

;

}

3，递归，求家谱树

家谱树的应用 ,如面包屑导航 首页 >手机类型 >CDMA手机 >公益PHP >递归应用

function

familytree(

$arr

,

$id

) {

$tree

=

array

();

foreach

(

$arr

as

$v

) {

if

(

$v

[

'id'

] ==

$id

) {

// 判断要不要找父栏目

if

(

$v

[

'parent'

] >0) { 

// parnet>0,说明有父栏目

$tree

=

array_merge

(

$tree

,familytree(

$arr

,

$v

[

'parent'

]));

}

$tree

[] =

$v

;

// 以找到上地为例

}

}

return

$tree

;

}

print_r(familytree(

$area

,8));

// 北京->海淀->上地

4，迭代，求家谱树

// 迭代,效率比递归高,代码也没多.

// 找家谱树推荐用迭代

function

tree(

$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(tree(

$area

,8));