check if at least one file was uploaded php

I have a form uploading multiple files:

 <?php
    $num_uploads = 3;
    $num = 0;
    while($num < $num_uploads)
    {
        echo '<div><input name="userfile[]" type="file" /></div>';
        $num++;
    }
 ?>

How do I check if at least one file was submitted wit开发者_开发百科h PHP or JavaScript?

Given how you're building the form, you'll have to account for a quirk in how PHP builds the files array.

foreach($_FILES['userfile']['error'] as $key => $err) {
    if ($err === UPLOAD_ERR_OK) {
       ... got at least one file ...
    }
}

For some moronic reason, instead of storing each file's upload data in its own seperate sub-array within $_FILES, PHP opts to instead spread each seperate error/name/tmp_name/etc... across the regular categories like so:

$_FILES = array(
   'userfile' => array(
       'name' => array(
            0 => 'name of file #1'
            1 => "name of file #2'
            etc...
       ),
       'tmp_name' => array(
            0 => 'temp name of file #1'
            1 => 'temp name of file #2'
    etc.. etc... etc..
    )
);

A much more reasonable and understandable version would've been

$_FILES = array(
      'userfile' => array(
           0 => array(
              'name' => 'name of file #1'
              'tmp_name' => 'temp name of file #1'
              ...
           ),
           1 => array(
              'name' => 'name of file #2'
              'tmp_name' => 'temp name of file #2'
              ...

but, alas, PHP has yet again saddled the world with an overly convoluted and cumbersome stupidity.

<?php
if (count($_FILES)) {
    // at least 1 file
}
?>

Try this,

$i = 0;
foreach ($_FILES as $file){
    if($file['size'] > 0){
         $i++;
    }        
}

now if the $i > 0 at least one file is uploaded. $i is the total numbers of file uploaded.