php - fatal error : Uncaught Error: Call to a member function format() on string

Question

<?php 

$servername = "localhost";
$username = "root";
$password = "";
$dbname = "hello";

// Create connection

$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
} 

echo "connected";

use Box\Spout\Reader\ReaderFactory;
use Box\Spout\Common\Type;

// Include Spout library 
include ('spout-2.4.3\src\Spout\Autoloader\autoload.php');

// check file name is not empty
if (!empty($_FILES['file']['name'])) {

    // Get File extension eg. 'xlsx' to check file is excel sheet
    $pathinfo = pathinfo($_FILES["file"]["name"]);

    // check file has extension xlsx, xls and also check 
    // file is not empty
   if (($pathinfo['extension'] == 'xlsx' || $pathinfo['extension'] == 'xls') 
           && $_FILES['file']['size'] > 0 ) {

        // Temporary file name
        $inputFileName = $_FILES['file']['tmp_name']; 

        // Read excel file by using ReadFactory object.
        $reader = ReaderFactory::create(Type::XLSX);

        // Open file
        $reader->open($inputFileName);
        $count = 1;
        $rows = array(); 

        // Number of sheet in excel file
        foreach ($reader->getSheetIterator() as $sheet) {

            // Number of Rows in Excel sheet
            foreach ($sheet->getRowIterator() as $row) {

                // It reads data after header. In the my excel sheet, 
                // header is in the first row. 
                if ($count> 1){

                $newDate = $row[4]-> format('d/m/Y');   

                $result=mysqli_query($conn,"INSERT INTO stud VALUES                         ('NULL','$row[1]','$row[2]','$row[3]','$newDate','$row[5]','$row[6]','$row[7]')");

                }
                $count++;
            }


        }

        // Close excel file
        $reader->close();

    } else {

        echo "Please Select Valid Excel File";
    }

} else {

    echo "Please Select Excel File";

}
?>

这是用于将 excel 文件导入到 mysql 数据库的 php 脚本，我在将日期从 excel 插入到 mysql 表时遇到错误。

$newDate = $row[4]-> format('d/m/Y');   
$result=mysqli_query($conn,"INSERT INTO stud VALUES           ('NULL','$row[1]','$row[2]','$row[3]','$newDate','$row[5]','$row[6]','$row[7]')");

我尝试格式化 row[4] ，但它显示“未捕获错误:调用字符串上的成员函数 format()”错误。有什么解决方案吗？

Excel文件: click to view excel which am working

Answer 1

更改行:

$newDate = $row[4]-> format('d/m/Y');

到

$newDate = new DateTime($row[4])->format('d/m/Y');

您正在对字符串调用 format 方法。