打平的数据内容如下：
{id: 1, name: '部门1', pid: 0},
{id: 2, name: '部门2', pid: 1},
{id: 3, name: '部门3', pid: 1},
{id: 4, name: '部门4', pid: 3},
{id: 5, name: '部门5', pid: 2},
{id: 6, name: '部门6', pid: 3},
{id: 7, name: '部门7', pid: 0},
]
pid 当前项父级
输出结果
{
"id": 1,
"name": "部门1",
"pid": 0,
"children": [
{
"id": 2,
"name": "部门2",
"pid": 1,
"children": [
{
"id": 5,
"name": "部门5",
"pid": 2,
"children": []
}
]
},
{
"id": 3,
"name": "部门3",
"pid": 1,
"children": [
{
"id": 4,
"name": "部门4",
"pid": 3,
"children": []
},
{
"id": 6,
"name": "部门6",
"pid": 3,
"children": []
}
]
}
]
},
{
"id": 7,
"name": "部门7",
"pid": 0,
"children": []
}
]
const arr = [
{id: 1, name: '部门1', pid: 0},
{id: 2, name: '部门2', pid: 1},
{id: 3, name: '部门3', pid: 1},
{id: 4, name: '部门4', pid: 3},
{id: 5, name: '部门5', pid: 2},
{id: 6, name: '部门6', pid: 3},
{id: 7, name: '部门7', pid: 0},
]
function tree(arr, pid = 0) {
const o = {};
arr.forEach(item => {
const pItem = o[item.pid] || (o[item.pid] = { children: [] });
o[item.id] = {
...item,
children: o[item.id]?.children || [],
};
pItem.children.push(o[item.id]);
})
return (pid != null && o[pid]?.children) || null
}
const t = tree(arr);
console.log(JSON.stringify(t, null, 2));
