Help with some PHP

ok /prog/ please help me out if any of you can. I NEED help, so please if you cannot or do not want to help at least keep trolling to a minimum.
So, I have this PHP object.
$connection = mysqli::__construct
(i.e. the object that tells the program I have made a connection to the database)
Now, I want to pass $con (which is an object) as an argument to a function, and then inside that function I want to call a method to the object $con, something like this:

function result($con) {
  $res = $con->query();
}
result($connection);
In this case the method is the query() method.
Well, the thing is I cannot do this, because, apparently, the $con that lives inside the function is NULL for some reason.
Even though since PHP 5 all objects that pass as arguments to functions pass by reference (or more precisely, by reference to their identifier), yet I tried to explicitly call it by reference, by putting a & in front of the argument, like this

function result(&$con) {
  $res = $con->query();
}
result($connection);
to no avail. $con is still NULL, if I do a var_dump() to it.
If I var_dump() the $connection, outside of the function, it will tell me that it's an object[etc], so I know that it initialises correctly. So I do something wrong when I pass it as an argument?..
On way to solve the problem, is to do the following

function() {
     $con = mysqli::__construct
     $res = $con->query();
}
but I do not want to create connections every time I  call the function, I want one "central" connection.
Any help will be much appreciated.

correction: in Line 5, I mean $connection, not $con.
It should read:
I want to pass $connection (which is an object)

Not Lisp; didn't read.

As i can't see the whole code, i'm just assuming.

If $con is a global variable, you must use the "global" keyword to use it inside another function.

Yes, PHP is shit.

>>4
The code (or at least the part of the code that is relevant here) very simply is this
<?php
session_start();

require_once 'database.php' //the database class that handles connections and stuff

$connection = Database::Connection(); //the static Connection() method of the class Database returns an object upon successful connection to the database, or NULL

$query = "somequery";
run_query($query, $connection);

function run_query($query, $con) {
   $result = $con->query($query);
   return $result;
}

?>

Well, this does not work, it gives me the error message that I am trying to do a method on a non-object item (that is the $con->query($query); within the function), and is right, because if you do a var_dump($con), first thing once you enter the function, it will display NULL.
And, again, the same var_dump outside of the function will display an object and not NULL.

I have not set the $connection to global, so I don't see why I should use that within the function.

>>5
oh, well, it should probably be something like this
$outcome = run_query($query, $connection);
but again, it does not matter, because the function is not working correctly anyway.

>>4
Not OP, but then doesn't that defeat the point of having a parameter anyways? If you have to actually use global $the arg; inside the function anyways, when calling foo($thearg);? Because then if I wanted to do foo($other); I'd have to change my function definition to use global $other; in it too.

This surely can't be right. I mean, as much of a bloody miscarriage PHP is, that still seems absurd.

Ok OP, I just did a simple test where I create a mysqli connection object and pass it to a function doing query on it and it works just fine. So I have no idea what's up with yours.

<?php
function do_query($sql, $con) {
    $res = $con->query($sql);
    return $res;
}
$conx = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
var_dump($conx);
var_dump(do_query('SHOW TABLES', $conx));
?>

>>8
Alright, thanks for that. Let me now check again what have I fucked up in there...

PHP is shit
.

Alright, got it sorted out, surprise surprise, I was overlooking something at another place of the script.
Thank you those who tried to help.


function query_shit(mysqli $conn) {
    // do shit here with $conn
}

$conn = new mysqli(...);

query_shit($conn);