woocommerce_cart_hash_key │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_cart_hash_key', 'wp_kama_woocommerce_cart_hash_key_filter' );

/**
 * Function for `woocommerce_cart_hash_key` filter-hook.
 * 
 * @param  $string 
 *
 * @return 
 */
function wp_kama_woocommerce_cart_hash_key_filter( $string ){

	// filter...
	return $string;
}

$string

-

Where the hook is called

'cart_hash_key'   => apply_filters( 'woocommerce_cart_hash_key', 'wc_cart_hash_' . md5( get_current_blog_id() . '_' . get_site_url( get_current_blog_id(), '/' ) . get_template() ) ),

Where the hook is used in WooCommerce