Question

我试图操纵多级类别树的结果，动态地给我一个如下所示的对象数组：

Array(
[0] => stdClass Object
    (
        [id] => 1
        [children] => Array
            (
                [0] => stdClass Object
                    (
                        [id] => 2
                    )

                [1] => stdClass Object
                    (
                        [id] => 3
                    )

            )

    )

[1] => stdClass Object
    (
        [id] => 9
    )

[2] => stdClass Object
    (
        [id] => 4
        [children] => Array
            (
                [0] => stdClass Object
                    (
                        [id] => 8
                    )

                [1] => stdClass Object
                    (
                        [id] => 5
                        [children] => Array
                            (
                                [0] => stdClass Object
                                    (
                                        [id] => 6
                                    )

                                [1] => stdClass Object
                                    (
                                        [id] => 7
                                    )

                            )

                    )

            )

    ))

它基本上告诉我们对象的id以及它是否有任何子节点。非常类似于Wordpress中的菜单构建器。

我想要做的是将这个数组转换为一个新的2级数组，如下所示：

Array(
[0] => Array
    (
        [0] => 1
        [1] => 9
        [2] => 4
    )

[1] => Array
    (
        [0] => 2
        [1] => 3
    )

[4] => Array
    (
        [0] => 8
        [1] => 5
    )

[5] => Array
    (
        [0] => 6
        [1] => 7
    ))

第一级的第一个键（[0]）将是没有父母的ID。所以ids 1,9和4是主要类别。子序列将是那些父母。因此，id 1有2和3作为子项，id 4有8和5作为子项，依此类推。

我很难搞清楚这一点。感谢您提前提供任何帮助！

Answer 1

使用递归函数可以实现这样的树结构展平。这是一个适用于您的树的示例。

function flatten($array_of_objects, $key = 0, &$result = []) {

    // iterate the objects in the array
    foreach ($array_of_objects as $object) {

        // add each object's id to the result
        $result[$key][] = $object->id;

        // if the object has children, make the recursive call on that array
        if (isset($object->children)) {
            flatten($object->children, $object->id, $result);
        }
    }
    return $result;
}

Answer 2

export default class App extends React.Component {
  state = {
    fontLoaded: false,
  };

  async componentDidMount() {
    await Font.loadAsync({
      'helvetica': helveticaFont,
      'roboto-condensed-light': robotoCondensedLight,
      'roboto-condensed-regular': robotoCondensedRegular,
      'roboto-condensed-bold': robotoCondensedBold,
    });
    this.setState({ fontLoaded: true });
  }

  render() {
    return (
      <View >
        {
          this.state.fontLoaded ? (
            <SignIn></SignIn>
          ) : null
        }
      </View>
    );
  }
}

操纵多维数组

2 个答案: