js数据整理

问题： 如何将给定数据结构（扁平对象数组）转换为具有层级嵌套的树状结构？

数据示例：

[
{
"id": 1,
"key": "",
"name": "系统管理",
"level": 1,
"type": 1,
"icon": "",
"code": "a001",
"parentcode": "",
"num": "a-1",
},
{
"id": 7,
"key": "",
"name": "日志管理",
"level": 1,
"type": 1,
"icon": "",
"code": "a004",
"parentcode": "",
"num": "a-7",
},
{
"id": 8,
"key": "roleadd",
"name": "角色管理",
"level": 2,
"type": 1,
"icon": "",
"code": "b001",
"parentcode": "a001",
"num": "1-1",
},
{
"id": 14,
"key": "logomanage",
"name": "日志管理",
"level": 2,
"type": 1,
"icon": null,
"code": "e001",
"parentcode": "a004",
"num": "1-1",
}
]

期望结果：

[
{
"id": 1,
"key": "",
"name": "系统管理",
"level": 1,
"type": 1,
"icon": "",
"code": "a001",
"parentcode": "",
"num": "a-1",
"children": [{
"id": 8,
"key": "roleadd",
"name": "角色管理",
"level": 2,
"type": 1,
"icon": "",
"code": "b001",
"parentcode": "a001",
"num": "1-1",
}]
},
{
"id": 7,
"key": "",
"name": "日志管理",
"level": 1,
"type": 1,
"icon": "",
"code": "a004",
"parentcode": "",
"num": "a-7",
"children": [{
"id": 14,
"key": "logomanage",
"name": "日志管理",
"level": 2,
"type": 1,
"icon": null,
"code": "e001",
"parentcode": "a004",
"num": "1-1",
}]
}
]

回答：

可以使用递归算法将扁平数据转换为树状结构。以下代码演示了如何实现：

let list = res[0]["__menus__"];

function transformData(data) {
  const result = [];
  for (const item of data) {
    const children = transformData(
      data.filter((d) => d.parentCode === item.code)
    );
    if (children.length) {
      result.push({ ...item, children });
    } else {
      result.push(item);
    }
  }
  return result;
}

console.log(transformData(list));

将给定的数据作为 res[0]['__menus__'] 传递给 transformdata 函数，该函数会递归循环数据，为具有相同父级代码的项目创建嵌套的树状结构。最终，函数返回一个具有层级嵌套的树状结构新数组，符合期望的结果。