Display Category and Subcategory In nested format

Question

I am working on category and sub category section where I want to display all the subcategory under their respective category.

It is something similar like Wordpress Category Sub Category display. I want to run this thing in Codeigniter.

Below is my array

    Array
    (
        [0] => Array
            (
                [name] => 1 Category
                [children] => Array
                    (
                        [0] => Array
                            (
                                [name] => 1 Sub Category
                            )

                        [1] => Array
                            (
                                [name] => 2nd 1 Sub Category 
                            )

                    )

            )

        [1] => Array
            (
                [name] => 6 Category
                [children] => Array
                    (
                        [0] => Array
                            (
                                [name] => 6 Sub Category
                                [children] => Array
                                    (
                                        [0] => Array
                                            (
                                                [name] => 2 Sub Category
                                                [children] => Array
                                                    (
                                                        [0] => Array
                                                            (
                                                                [name] => 7 Sub Category
                                                            )

                                                    )

                                            )

                                    )

                            )

                    )

            )

    )

And my desire out is:

    1 Category 
       - 1 Sub Category
       - 2nd 1 Sub Category
    6 Category
       - 6 Sub Category
           - 2 Sub Category
               - 7 Sub Category

Another Desired Output :

<select>
<option>1 Category</option>
<option>- 1 Sub Category</option>
<option>- 2nd 1 Sub Category</option>
<option>6 Category</option>
<option>- 6 Sub Category</option>
<option>- - 2 Sub Category</option>
<option>- - - 7 Sub Category</option>
</select>

I hope i am clear with my question and desired output.

Answer 1

I have created a function which returns ul,li result for your input.. Try this..

get_category($array);

function get_category($array) {
    echo '<ul>';
    foreach($array as $category) {
        echo '<li>';
        echo $category['name'];
        if(isset($category['children'])) {
            get_category($category['children']);
        }
        echo '</li>';
    }
    echo '</ul>';
}

Update for Select output

echo '<select>';
get_category($array);
echo '</select>';

function get_category($array, $prefix = '') {
    foreach($array as $category) {
        echo '<option>';
        echo $prefix . $category['name'];
        echo '</option>';
        if(isset($category['children'])) {
            get_category($category['children'], $prefix.'- ');
        }
    }
}