WooCommerce - Get values of product custom attribute

woocommerce-custom-attribute.php

<?php 
/* When we make custom product attribute in WooCommerce, they are registered as a custom taxonomy. 
 * So we can use WordPress function get_the_terms() to retrieve them.
 * When register these custom taxonomy, WooCommerce adds a prefix of pa_ to our custom product attribute.
 * So if we create an attribute called Height, who's slug is 'height', then the custom taxonomy would be 'pa_height'.
 * Now we are going to retrieve all terms in this attribute (height) of a product.
 */
$pa_height = get_the_terms( $product->id, 'pa_height');
if ( ! empty( $pa_height ) && ! is_wp_error( $pa_height ) ) { 
  foreach ( $pa_height as $pa_height_item ) {
	  echo $pa_height_item->name;
  }
} ?>