PHP > Invalid Argument supplied for foreach() - php

Question

In short, I am trying to figure out what is wrong with my foreach statement. I have been trying to work on finding the error for over a day know and I'm running out of time. This program is supposed to parse a json array and post it up to a mysqli database.
<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
$a = print_r(var_dump($GLOBALS),1);
echo htmlspecialchars($a);
$servername = "#";
$username = "#";
$password = "#";
$dbname = "#";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
echo "Connection Successful : ";
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
// Read JSON file
$jsondata = file_get_contents('scripts/AUDIT_DIR/report.json');
echo "JSON File Read : ";
// Convert and Loop
$item = json_decode($jsondata, true);
echo "JSON File Decoded : ";
foreach($item as $arr)
{
$id = $arr["id"];
$hostname = $arr["hostname"];
$ip = $arr["ip"];
$package = $arr["package"];
$publisher = $arr["publisher"];
$origin = $arr["origin"];
$version = $arr["version"];
$size = $arr["size"];
$sql = "INSERT INTO testtable(id, hostname, ip, package, publisher, origin, version, size)
VALUES ('10', '$hostname', '$ip', '$package', '$publisher', '$origin', '$version', '$size')";
if (mysqli_query($conn, $sql))
{
echo "New record created successfully : ";
}
else
{
echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
}
?>

Answer 1

You likely have an invalid return from your json_decode() you can check this with a var_dump($item); after your json_decode()
In php json_decode() will return NULL if the json cannot be decoded or if the encoded data is deeper than the recursion limit. http://php.net/manual/en/function.json-decode.php
You need to properly guard for such a case that $item === null and not assume you will always get a valid return for your foreach() params.
Example showing your error happens when $item = null
https://3v4l.org/oNr8P