<?php
    function find_days($start_date, $end_date) {
    $response = new stdClass();
    try {
    $sdate = new DateTime($start_date);
    $edate = new DateTime($end_date);
    $dateInterval = $edate->diff($sdate);
    $response->status = true;
    $response->result = $dateInterval;
    return $response;
    } catch (Exception $e) {
    $response->status = false;
    $response->result = 'Invalid Date Format';
    return $response;
    }
    } 
    ?>            
    Start Date: <input type="date" name="sdate" placeholder="start date" /> 
    End Date: <input type="date" name="edate" placeholder="end date" /> 
    <input type="submit" value="Find Days" />
    <?php
           if (isset($_POST['sdate']) && $_POST['sdate']) {
            $start_date = $_POST['sdate'];
            $end_date = $_POST['edate'];
            //now call the function
            $days_array = find_days($start_date, $end_date);
            if ($days_array->status) {
            echo " <input  type='text' name='day' 
            value='.$days_array>result>days.' />";
            $day = $_POST['day'];                   
            $query   = "INSERT into cart (date,edate,days) 
            VALUES('$start_date','$end_date','$day')";
            $success = $conn->query($query);
            if (!$success) {
            die("Couldn't enter data: ".$conn->error);  
            }
            } else {
                echo $days_array->result;
            }
        }

我的代码运行得很好。但结果只显示在屏幕上。因此，我尝试将结果存储在文本框中，然后以通常的方式插入到表中。但是我在第45行遇到了一个错误“catchable fatal error:dateinterval类的对象无法转换为c:\xampp\htdocs\date.php中的字符串”，我不知道如何纠正这个错误。。请帮我解决这个问题。