1. 對(duì)每一個(gè)children添加一個(gè)level，來(lái)表示它的層級(jí)

function deepGetValueItem(item, index) {
      let deepIndex = index || 0
      deepIndex += 1
      for (let i = 0; i < item.length; i++) {
        item[i]['level'] = deepIndex
        if (item[i].children) deepGetValueItem(item[i].children, deepIndex)
      }
    }

2. 每一層級(jí)下都與最外層的索引一致

function treeData(arr, sIndex = undefined) {
  for (let i = 0; i < arr.length; i++) {
    arr[i]._index = sIndex || String(i);
    if (arr[i].children && arr[i].children.length > 0) {
      treeData(arr[i].children, arr[i]._index);
    }
  }
}
treeData(data);