PHP -- Undefined index: - php

Question

I am having an issue with undefined error in my php. After research I know I know I should use isset but I'm not sure how to implement it. Here is the peice of code that causes the issue:
if (($_FILES["file"]["type"] == "video/mp4") && ($_FILES["file"]["size"] < 20000))
{
Should I put the isset inside the if function before each $_FILES or where should it go ?
Here is the full piece of code, as you will probably notice I am quite new to PHP:
$ivalid_file='0';
if (($_FILES["file"]["type"] == "video/mp4") && ($_FILES["file"]["size"] < 20000))
{
if ($_FILES["file"]["error"] > 0)
{
echo "Return Code: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br />";
echo "Type: " . $_FILES["file"]["type"] . "<br />";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";
if (file_exists("uploads/" . $_FILES["file"]["name"]))
{
echo $_FILES["file"]["name"] . " already exists. ";
}
else
{
move_uploaded_file($_FILES["file"]["tmp_name"],
"uploads/" . $_FILES["file"]["name"]);
echo "Stored in: " . "uploads/" . $_FILES["file"]["name"];
}
}
}
else
{
echo "invalid_file";
}

Answer 1

As far as I understand, you want to know how to check if the file was ever uploaded and how to implement it in code. All you gotta do is, wrap you entire code in an if block which checks if $_FILES['files'] is set like so:
//Check if "file" exists here:
if(isset($_FILES["file"])) {
$ivalid_file='0';
if (($_FILES["file"]["type"] == "video/mp4") && ($_FILES["file"]["size"] < 20000))
{
if ($_FILES["file"]["error"] > 0)
{
echo "Return Code: " . $_FILES["file"]["error"] . "<br />";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "<br />";
echo "Type: " . $_FILES["file"]["type"] . "<br />";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb<br />";
echo "Temp file: " . $_FILES["file"]["tmp_name"] . "<br />";
if (file_exists("uploads/" . $_FILES["file"]["name"]))
{
echo $_FILES["file"]["name"] . " already exists. ";
}
else
{
move_uploaded_file($_FILES["file"]["tmp_name"],
"uploads/" . $_FILES["file"]["name"]);
echo "Stored in: " . "uploads/" . $_FILES["file"]["name"];
}
}
}
else
{
echo "invalid_file";
}
} else {
// Display appropriate error
}