Use a loop to look through POST variables - php

Question

I'm trying to make a POST method that will receive a value from a table (that is dynamically generated). This value will be equal to a company name, and a hidden field will be there that is equal to company name + "id" appended to it.
Here's my code:
if(isset($_POST))
{
foreach ( $users as $balance_user ) {
if(isset($_POST[$balance_user]))
{
//update user meta with new balance
$newBalance = $_POST[$balance_user];
$postedID = $_POST[$balance_user.'id'];
update_user_meta($postedID, 'balance', $newBalance);
}
}
}
I keep getting the error Illegal offset type in isset or empty. Can I not pass variables in that way? For example if a company is called Acme, and that particularly named input has a value in it, I want to loop through all of the companies in the POST method, and if that part of the loop equals the company passed in the variable, it should do something.

Answer 1

Add these three lines to see the data, as others have indicated, clearly you are assuming some value is in $balance_user which is not there, or is different.
echo '<pre>:';
var_dump($balance_user);
echo ':</pre>';
if(isset($_POST[$balance_user]))
The pre makes it easier to read the debugging output. the :..: will show null values.
Once you run that, you will probably discover that one of your entries in $users is empty.
The output order will show you where that empty user value is.
However:
$postedID = $_POST[$balance_user.'id'];
That could be the error source as well, is there a post value that is. say, $balance_user == fred
fredid
if there isn't, of course you will instantly get that error. You aren't giving the line number of the error so I can't tell which it is, the line number will show it instantly.