woocommerce_order_get_subtotal │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_order_get_subtotal', 'wp_kama_woocommerce_order_get_subtotal_filter', 10, 2 );

/**
 * Function for `woocommerce_order_get_subtotal` filter-hook.
 * 
 * @param  $condition 
 * @param  $that      
 *
 * @return 
 */
function wp_kama_woocommerce_order_get_subtotal_filter( $condition, $that ){

	// filter...
	return $condition;
}

$condition

-

$that

-

Where the hook is called

return apply_filters( 'woocommerce_order_get_subtotal', (float) $subtotal, $this );

Where the hook is used in WooCommerce