fix: minor bug

server/controllers/add_cart.php

@@ -19,7 +19,7 @@
         $stmt->bind_param("sss", $item_id, $cart_username, $item_quantity);
         $result = $stmt->execute();
         if (!$result) {
-            $response = array("success" => "false", "message" => $stmt.error);
+            $response = array("success" => "false", "message" => $stmt->error);
             die ("Error in query execution: " . $stmt->error);
         } else {
             $response = array("success" => "true", "message" => "item has been added");

server/controllers/cartdetail_query.php

@@ -21,7 +21,7 @@
 
 
         if (!$result) {
-            $response = array("success" => "false", "message" => $stmt.error);
+            $response = array("success" => "false", "message" => $stmt->error);
             die ("Error in query execution: " . $stmt->error);
         } else {
             $response = array("success" => "true", "message" => "showing ".$cart_username."'s cart", "data" => $resultSet->fetch_all(MYSQLI_ASSOC));

server/controllers/sell_item.php

@@ -35,7 +35,7 @@
         $stmt->bind_param("issssss", $item_id, $name, $picture_path, $description, $price, $quantity, $seller_username);
         $result = $stmt->execute();
         if (!$result) {
-            $response = array("success" => "false", "message" => $stmt.error);
+            $response = array("success" => "false", "message" => $stmt->error);
             die ("Error in query execution: " . $stmt->error);
         } else {
             $response = array("success" => "true", "message" => "item has been added");