如何通过父id-s (JavaScript)加深数组

function deepenArray(arr) {
  const result = {};
  
  arr.forEach(item => {
    const parentId = item.parentId;
    
    if (!parentId || parentId === "") {
      // 当前元素没有父id，添加到根级别
      result[item.id] = item;
    } else {
      // 查找父id对应的节点，并将当前元素添加为其子节点
      const parent = result[parentId];
      
      if (!parent.children) {
        parent.children = [];
      }
      
      parent.children.push(item);
    }
  });
  
  return Object.values(result);
}

// 示例数据
const data = [
  { id: 1, name: "A", parentId: "" },
  { id: 2, name: "B", parentId: "" },
  { id: 3, name: "A1", parentId: 1 },
  { id: 4, name: "A2", parentId: 1 },
  { id: 5, name: "B1", parentId: 2 },
  { id: 6, name: "B2", parentId: 2 },
  { id: 7, name: "A11", parentId: 3 },
  { id: 8, name: "A12", parentId: 3 },
];

const deepenedArray = deepenArray(data);
console.log(deepenedArray);