Add arrows to menu items

functions.php

<?php

/**
 * Add arrows to menu items
 * @author Bill Erickson
 * @link http://www.billerickson.net/code/add-arrows-to-menu-items/
 * 
 * @param string $item_output, HTML output for the menu item
 * @param object $item, menu item object
 * @param int $depth, depth in menu structure
 * @param object $args, arguments passed to wp_nav_menu()
 * @return string $item_output
 */
function be_arrows_in_menus( $item_output, $item, $depth, $args ) {

	if( in_array( 'menu-item-has-children', $item->classes ) ) {
		$arrow = 0 == $depth ? '<i class="icon-angle-down"></i>' : '<i class="icon-angle-right"></i>';
		$item_output = str_replace( '</a>', $arrow . '</a>', $item_output );
	}

	return $item_output;
}
add_filter( 'walker_nav_menu_start_el', 'be_arrows_in_menus', 10, 4 );