警告:end(）要求参数1为数组，第31行给出的字符串

我对php还很陌生，正在尝试创建多个图像上传表单（我正在循环这个过程）。出于某种原因，我收到了这个警告（warning:end（）希望参数1是数组，第31行给出的字符串），这是($temp = ( $_FILES["file"]["name"][$i]);) 行

请帮我一下。此外，在上传之前，我正在努力确保图像文件的格式正确，所以我是否必须循环一次以确保它们是正确的格式，然后再次循环以进行上传？Ps.忽略SQL注入问题，稍后会添加这些问题。谢谢Php

<?php
ini_set('display_errors', 1); error_reporting(E_ALL);
ob_start();
session_start();
include 'connect.php';

if ($_POST)
{
 //get form data

 $Listingname = addslashes(strip_tags($_POST['Listingname']));
 $Location = addslashes(strip_tags($_POST['Location']));
 $nobed = addslashes(strip_tags($_POST['nobed']));
 $zip = addslashes(strip_tags($_POST['zip']));
 $price = ($_POST['price']);
 $username=($_POST[$_SESSION['username']]);
 if (!$Listingname||!$nobed||!$nobed||!$zip||!$price)
    echo "Please fill out all fields"; 
    else 
    {$allowedExts = array("gif", "jpeg", "jpg", "png");
    $temp = $_FILES["file"]["name"];
    for($i=0;$i<count($temp);$i++)
$temp = ( $_FILES["file"]["name"][$i]);
$extension = end($temp);
if ((($_FILES["file"]["type"][$i] == "image/gif")
|| ($_FILES["file"]["type"][$i] == "image/jpeg")
|| ($_FILES["file"]["type"][$i] == "image/jpg")
|| ($_FILES["file"]["type"][$i] == "image/pjpeg")
|| ($_FILES["file"]["type"][$i] == "image/x-png")
|| ($_FILES["file"]["type"][$i] == "image/png"))
&& ($_FILES["file"]["size"][$i] < 400000)
&& in_array($extension, $allowedExts))
  {
  if ($_FILES["file"]["error"][$i] > 0)
    {
    echo "Return Code: " . $_FILES["file"]["error"][$i] . "<br>";
    }
  else
    {
    echo "Upload: " . $_FILES["file"]["name"][$i] . "<br>";
    echo "Type: " . $_FILES["file"]["type"][$i] . "<br>";
    echo "Size: " . ($_FILES["file"]["size"][$i] / 1024) . " kB<br>";
    echo "Temp file: " . $_FILES["file"]["tmp_name"][$i] . "<br>";
    if (file_exists("upload/" . $_FILES["file"]["name"][$i]))
      {
      echo $_FILES["file"]["name"][$i] . " already exists please add another file, or change the. ";
      }
    else
      {
        $photo=$_FILES["file"]["name"][$i];
      move_uploaded_file($_FILES["file"]["tmp_name"][$i],
      "upload/$photo");
      echo "Stored in: " . "upload/" . $_FILES["file"]["name"][$i];
      }
    }
  }
else
{
  echo "Invalid file" and die("Can not load picture");
  }

    {
       $username=$_SESSION['username'];
           //register into database
            mysqli_query($con,"INSERT INTO Listing (username,Listingname,Location,nobed,zip,price,pic1) VALUES 
                ('$username','$Listingname','$Location','$nobed','$zip','$price','$photo');") or die(mysqli_error());

            echo "Listing Added";
    }
       }
    }

else
{
?>
<form action="Submitlisting5.php" method="post"
enctype="multipart/form-data">
Listing Name:<br />
<input type='text' name='Listingname'><p />
Location:<br />
<input type='text' name='Location'><p />
Number of Beds:<br />
<input type='test' name='nobed'><p />
Zip:<br />
<input type='text' name='zip'><p />
Price:<br />
<input type='text' name='price'><p />

<label for="file">Pic1(File must be exceed 4mb):</label>
<input type="file" name="file[]" id="file[]"><br>
<label for="file">Pic2(File must be exceed 4mb):</label>
<input type="file" name="file[]" id="file[]"><br>
<br>
<input type='submit' name='submit' value='Submit'>
</form>
<?php
}

?>

刚试过这个，但现在它直接转到无法上传图片

 {$allowedExts = array("gif", "jpeg", "jpg", "png");
    for($i=0;$i<4;$i++){
$temp = ( $_FILES["file"]["name"]);
$extension = $temp;
if ((($_FILES["file"]["type"][$i] == "image/gif")
|| ($_FILES["file"]["type"][$i] == "image/jpeg")
|| ($_FILES["file"]["type"][$i] == "image/jpg")
|| ($_FILES["file"]["type"][$i] == "image/pjpeg")
|| ($_FILES["file"]["type"][$i] == "image/x-png")
|| ($_FILES["file"]["type"][$i] == "image/png"))
&& ($_FILES["file"]["size"][$i] < 400000)
&& in_array($extension, $allowedExts))

第三次试验

for($i=0;$i<4;$i++){

if ((($_FILES["file"]["type"][$i] == "image/gif")
|| ($_FILES["file"]["type"][$i] == "image/jpeg")
|| ($_FILES["file"]["type"][$i] == "image/jpg")
|| ($_FILES["file"]["type"][$i] == "image/pjpeg")
|| ($_FILES["file"]["type"][$i] == "image/x-png")
|| ($_FILES["file"]["type"][$i] == "image/png"))
    && ($_FILES["file"]["size"][$i] < 400000))