JS tree结构数据获取父节点

 const getParentKey = (key, tree) => {
        let parentKey;
        for (let i = 0; i < tree.length; i++) {
          const node = tree[i];
            // 判断是不是顶级父
          if (node.key == key) {
            return node.key;
          }
          if (node.children) {
            if (node.children.some((item) => item.key === key)) {
              parentKey = node.key;
            } else if (getParentKey(key, node.children)) {    // 必须判断是否有返回值
              parentKey = getParentKey(key, node.children);
            }
          }
        }
        return parentKey;
      };
      var tree = [
        {
          key: "a",
          value: "1",
          children: [
            { key: "b", value: "2" },
            { key: "c", value: "3", children: [{ key: "d", value: "4" }] },
          ],
        },
        {
          key: "a1",
          value: "11",
          children: [
            { key: "b1", value: "21" },
            { key: "c1", value: "31", children: [{ key: "d1", value: "41" }] },
          ],
        },
      ];
      console.log(getParentKey("d1", tree));    //"c1"
getParentKey3("a",tree);    //"a"
getParentKey3("d",tree);    //"c"