Array
(
    [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] => Elementary Math
                            [slug] => elementary-math
                            [id] => 1743
                        )

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

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

                    [4] => Array
                        (
                            [name] => Trigonometry
                            [slug] => trigonometry
                            [id] => 1729
                        )

                )

        )

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

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Elementary Science
                            [slug] => elementary-science
                            [id] => 1759
                        )

                )

        )

    [1856] => Array
        (
            [parent_category_id] => 1856
            [parent_category] => Array
                (
                    [id] => 1856
                    [slug] => test-prep-exams
                    [name] => Test Prep and Exams
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => TOEFL
                            [slug] => toefl
                            [id] => 1857
                        )

                )

        )

)