PHP List数据集/数组转换成树状结构Tree
一、引用链接法
/**
* 数据列表转换成树
*
* @param array $dataArr 数据列表
* @param integer $rootId 根节点ID
* @param string $pkName 主键
* @param string $pIdName 父节点名称
* @param string $childName 子节点名称
*
* @return array 转换后的树
*/
function ListToTree($dataArr, $rootId = 0, $pkName = 'cc_id', $pIdName = 'parent_id', $childName = 'children')
{
$tree = [];
if (is_array($dataArr))
{
//1.0 创建基于主键的数组引用
$referList = [];
foreach ($dataArr as $key => & $sorData)
{
$referList[$sorData[$pkName]] =& $dataArr[$key];
}
//2.0 list 转换为 tree
foreach ($dataArr as $key => $data)
{
$pId = $data[$pIdName];
if ($rootId == $pId) //一级
{
$tree[] =& $dataArr[$key];
}
else //多级
{
if (isset($referList[$pId]))
{
$pNode =& $referList[$pId];
$pNode[$childName][] =& $dataArr[$key];
}
}
}
}
return $tree;
}
主要通过引用指向同一地址的技术手段解决问题。
$referList的每个元素指向$dataArr数组的元素地址。遍历时，通过将$rootId下的元素指向$tree[]，非$rootId下的元素指向父级的$referList[$pId]的$childName元素，遍历完毕后，链接形成整个树结构。
转换前：
{
"cc_id": 1,
"cc_name": "语文",
"cc_path": "0/1/",
"parent_id": 0,
"children": []
},
{
"cc_id": 2,
"cc_name": "数学",
"cc_path": "0/1/2/",
"parent_id": 1,
"children": []
},
{
"cc_id": 3,
"cc_name": "英语",
"cc_path": "0/3/",
"parent_id": 0,
"children": []
},
{
"cc_id": 9,
"cc_name": "一年级",
"cc_path": "0/1/9/",
"parent_id": 1,
"children": []
},
{
"cc_id": 10,
"cc_name": "二年级",
"cc_path": "0/1/10/",
"parent_id": 1,
"children": []
},
{
"cc_id": 11,
"cc_name": "三年级",
"cc_path": "0/1/11/",
"parent_id": 1,
"children": []
}
转换后：
{
"cc_id": 1,
"cc_name": "语文",
"cc_path": "0/1/",
"parent_id": 0,
"children": [
{
"cc_id": 2,
"cc_name": "数学",
"cc_path": "0/1/2/",
"parent_id": 1,
"children": []
},
{
"cc_id": 9,
"cc_name": "一年级",
"cc_path": "0/1/9/",
"parent_id": 1,
"children": []
},
{
"cc_id": 10,
"cc_name": "二年级",
"cc_path": "0/1/10/",
"parent_id": 1,
"children": []
},
{
"cc_id": 11,
"cc_name": "三年级",
"cc_path": "0/1/11/",
"parent_id": 1,
"children": []
}
]
},
{
"cc_id": 3,
"cc_name": "英语",
"cc_path": "0/3/",
"parent_id": 0,
"children": []
}
二、递归法
/**
* 采用递归将数据列表转换成树
*
* @param array $dataArr 数据列表
* @param integer $rootId 根节点ID
* @param string $pkName 主键
* @param string $pIdName 父节点名称
* @param string $childName 子节点名称
*
* @return array 转换后的树
*/
function ListToTreeRecursive($dataArr, $rootId = 0, $pkName = 'cc_id', $pIdName = 'parent_id', $childName = 'children')
{
$arr = [];
foreach ($dataArr as $sorData)
{
if ($sorData[$pIdName] == $rootId)
{
$sorData[$childName] = ListToTreeRecursive($dataArr, $sorData[$pkName]);
$arr[] = $sorData;
}
}
return $arr;
}