PHP Variable Scope issue?

Question

I'm writing a function and it uses the $PDO variable in another file. I included the file at the beginning, but it's saying undeclared variable. I'm assuming it's because it's out of scope.

  require './db/db.php';
  session_start();

    function createUser($username) {

    }

What can I do to be able to reference the variable $PDO which is my PDO instance to use the database in my functions?

Answer 1

Assuming you didn't declare the "PDO instance" inside any external function or class, you should just pass it to the function as a parameter. So (if you're talking about your createUser function)

createUser($PDO, $username) { }

And you'd call it like this: createUser($PDO, 'Foo'); .

Answer 2

Pass $PDO as an argument;

function function_name($PDO)
{
    // Your function code
}

Answer 3

Either pass the variable to the function as an argument, or put

global $PDO;

in the function.