Array
(
    [1840] => Array
        (
            [parent_category_id] => 1840
            [parent_category] => Array
                (
                    [id] => 1840
                    [slug] => art-design
                    [name] => Art and Design
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Art History
                            [slug] => art-history
                            [id] => 1841
                        )

                )

        )

    [1760] => Array
        (
            [parent_category_id] => 1760
            [parent_category] => Array
                (
                    [id] => 1760
                    [slug] => english-reading
                    [name] => English and Reading
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Literature
                            [slug] => literature
                            [id] => 1766
                        )

                )

        )

    [1772] => Array
        (
            [parent_category_id] => 1772
            [parent_category] => Array
                (
                    [id] => 1772
                    [slug] => history-social-studies
                    [name] => History and Social Studies
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => American History
                            [slug] => american-history
                            [id] => 1773
                        )

                    [1] => Array
                        (
                            [name] => Classics
                            [slug] => classics
                            [id] => 1783
                        )

                    [2] => Array
                        (
                            [name] => Psychology
                            [slug] => psychology
                            [id] => 1781
                        )

                    [3] => Array
                        (
                            [name] => World History
                            [slug] => world-history
                            [id] => 1775
                        )

                )

        )

    [1723] => Array
        (
            [parent_category_id] => 1723
            [parent_category] => Array
                (
                    [id] => 1723
                    [slug] => math
                    [name] => Math
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Algebra 1
                            [slug] => algebra-1
                            [id] => 1725
                        )

                    [1] => Array
                        (
                            [name] => Algebra 2
                            [slug] => algebra-2
                            [id] => 1726
                        )

                    [2] => Array
                        (
                            [name] => Calculus
                            [slug] => calculus
                            [id] => 1730
                        )

                    [3] => Array
                        (
                            [name] => Prealgebra
                            [slug] => prealgebra
                            [id] => 1724
                        )

                    [4] => Array
                        (
                            [name] => Precalculus
                            [slug] => precalculus
                            [id] => 1728
                        )

                )

        )

    [1744] => Array
        (
            [parent_category_id] => 1744
            [parent_category] => Array
                (
                    [id] => 1744
                    [slug] => science
                    [name] => Science
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Astronomy
                            [slug] => astronomy
                            [id] => 1758
                        )

                    [1] => Array
                        (
                            [name] => Physics
                            [slug] => physics
                            [id] => 1748
                        )

                )

        )

)