<?php
    if (isset($_POST["submit"])) // check if a file has been submitted and if it is an image
    {
        $dir = "uploads/"; // directory where files are going
        $file = $dir . basename($_FILES["file_uploaded"]["name"]); // file's path and name uploaded
   
        $file_type  = pathinfo($file, PATHINFO_EXTENSION); // check file's type
        if ($file_type == "PNG" || $file_type == "JPG" || $file_type == "GIF" || $file_type == "JPEG")
       {
           echo "File is an image  " . $file_type . ".";
       }
       else 
       {
            echo "File is not an image!";
       }
   }
?>