All post categories dropdown in WordPress

<selectname=”event-dropdown”onchange=’document.location.href=this.options[this.selectedIndex].value;’>

            <!–<option value=””><?php //echo esc_attr(__(‘Select Category’)); ?></option> –>

            <?php

                $option = ‘<option value=”‘ . get_option(‘home’) . ‘/category/”>All Categories</option>’; // change category to your custom page slug

                $categories = get_categories();

                foreach ($categories as $category) {

                    $option .= ‘<option value=”‘.get_option(‘home’).’/category/’.$category->slug.'”>’;

                    $option .= $category->cat_name;

                    //$option .= ‘ (‘.$category->category_count.’)’;

                    $option .= ‘</option>’;

                }

                echo $option;

            ?>

        </select>