Warning: Invalid argument supplied for foreach() - uploading photos form - php

Question

Hi I'm new to php and keep getting this error: "Warning: Invalid argument supplied for foreach() in /home/site/folder/upload.php on line 61."
I'm trying to build a form in which users can upload one or more photos automatically to a directory to then be displayed else where.
Whenever I use this form I created it functions properly on my website but unfortunately it keeps printing that error out and would like it to go away. Here is my code I'm working with:
<div>
<form action="upload.php" enctype="multipart/form-data" method="POST">
<input type="file" name="images[]" multiple="multiple"/>
<input type="submit" name="submit" value="upload images"/>
<form/>
<?php
// check if uploads directory exists
$dir = "images/";
if(!is_dir($dir))
{
echo "Directory not found, let's create the folder.";
mkdir($dir,"0777", true);
}
$countimg = 0;
$allimg = 0;
foreach($_FILES["images"]["name"] as $k=>$name)
{
$allimg++;
$imgname = $_FILES["images"]["name"][$k];
$sizeimg = $_FILES["images"]["size"][$k];
$tmpname = $_FILES["images"]["tmp_name"][$k];
//2.
$extension = strtolower(pathinfo($dir.$imgname, PATHINFO_EXTENSION));
if($extension=='png' || $extension=='jpg' ||$extension=='jpeg' ||$extension=='gif')
{
if($sizeimg < 2097152){
if(!file_exists($dir.$imgname)){
//1.
if(move_uploaded_file($tmpname,$dir.$imgname))
{
$countimg++;
}
}
}
}
}
echo "You are trying to upload $allimg images".'<br>';
echo "From $allimg image(s) - $countimg was/were uploaded with success".'<br>';
$z = $allimg - $countimg;
echo "$z image(s) were not uploaded: Not an image, over 2MB, or already uploaded.";
?>
</div>

Answer 1

Try
if (count($_FILES)) {
foreach($_FILES["images"]["name"] as $k=>$name) {
....
}
}

Answer 2

I tested your script, it works fine. The error message appears because you are not checking that a file got uploaded before starting the foreach. If I land on the page, the PHP code will still be triggered. To fix this, you may use the below:
<div>
<form action="upload.php" enctype="multipart/form-data" method="POST">
<input type="file" name="images[]" multiple="multiple"/>
<input type="submit" name="submit" value="upload images"/>
<form/>
<?php
if( $_POST['submit'] ) {
$dir = "images/";
if(!is_dir($dir))
{
echo "Directory not found, let's create the folder.";
mkdir($dir,"0777", true);
}
$countimg = 0;
$allimg = 0;
foreach($_FILES["images"]["name"] as $k=>$name)
{
$allimg++;
$imgname = $_FILES["images"]["name"][$k];
$sizeimg = $_FILES["images"]["size"][$k];
$tmpname = $_FILES["images"]["tmp_name"][$k];
//2.
$extension = strtolower(pathinfo($dir.$imgname, PATHINFO_EXTENSION));
if($extension=='png' || $extension=='jpg' ||$extension=='jpeg' ||$extension=='gif')
{
if($sizeimg < 2097152){
if(!file_exists($dir.$imgname)){
//1.
if(move_uploaded_file($tmpname,$dir.$imgname))
{
$countimg++;
}
}
}
}
}
echo "You are trying to upload $allimg images".'<br>';
echo "From $allimg image(s) - $countimg was/were uploaded with success".'<br>';
$z = $allimg - $countimg;
echo "$z image(s) were not uploaded: Not an image, over 2MB, or already uploaded.";
}
?>
</div>
if( $_POST['submit'] ) will ensure that the form is submitted prior to running the rest of the PHP code.