Custom sorting options - alphabet order - WooCommerce

function.php

<?php
// Custom sorting options
add_filter( 'woocommerce_get_catalog_ordering_args', 'custom_woocommerce_get_catalog_ordering_args' );
function custom_woocommerce_get_catalog_ordering_args( $args ) {
  	$orderby_value = isset( $_GET['orderby'] ) ? woocommerce_clean( $_GET['orderby'] ) : apply_filters( 'woocommerce_default_catalog_orderby', get_option( 'woocommerce_default_catalog_orderby' ) );

	if ('title_asc' == $orderby_value) {
		$args['orderby'] = 'title';
		$args['order'] = 'ASC';
		$args['meta_key'] = '';
	}elseif ('title_desc' == $orderby_value) {
		$args['orderby'] = 'title';
		$args['order'] = 'DESC';
		$args['meta_key'] = '';
	}

	return $args;
}