JavaScript将数据分组到2级深的树视图中

const data = [
  { id: 1, name: 'Item 1', categoryId: 1 },
  { id: 2, name: 'Item 2', categoryId: 1 },
  { id: 3, name: 'Item 3', categoryId: 2 },
  { id: 4, name: 'Item 4', categoryId: 2 },
  { id: 5, name: 'Item 5', categoryId: 3 }
];

const categories = [
  { id: 1, name: 'Category 1' },
  { id: 2, name: 'Category 2' },
  { id: 3, name: 'Category 3' }
];

function createTree(data, categories) {
  const categoryMap = new Map();
  categories.forEach(category => {
    categoryMap.set(category.id, { ...category, children: [] });
  });

  const tree = [];
  data.forEach(item => {
    const category = categoryMap.get(item.categoryId);
    if (category) {
      category.children.push({ id: item.id, name: item.name });
    }
  });

  categoryMap.forEach(category => {
    tree.push(category);
  });

  return tree;
}

const tree = createTree(data, categories);
console.log(JSON.stringify(tree, null, 2));