Question

In there
exist a simple example of MVC in PHP. the problem is, this example just work when this

$action = $_GET['action'];
if(function_exists($action) && !substr($action,0,1)=="_"){
    $action();
}else{
    echo "<h1>404 Page Not Found</h1><p>The page you requested could not be found</p>";
}

changed to:

    $action = $_GET['action'];
if(function_exists($action) || !substr($action,0,1)=="_"){
    $action();
}else{
    echo "<h1>404 Page Not Found</h1><p>The page you requested could not be found</p>";
}

&& changed to ||. or completely !substr($action,0,1)==”_” removed. What does this line is not allowed to run $action?

=======================

Edit: Problem is that router don’t work with &&!

Answer 1

Solved with change

From:

if(function_exists($action) && !substr($action,0,1)=="_")

To:

if(function_exists($action) && !(substr($action,0,1)=="_"))