Array
(
    [1880] => Array
        (
            [parent_category_id] => 1880
            [parent_category] => Array
                (
                    [id] => 1880
                    [slug] => engineering
                    [name] => Engineering
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Mechanical Engineering
                            [slug] => mechanical-engineering
                            [id] => 1881
                        )

                )

        )

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

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Grammar
                            [slug] => grammar
                            [id] => 1761
                        )

                )

        )

    [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
                        )

                )

        )

)