Question

I’m having a bit of trouble understanding includes and function scopes in PHP, and a bit of Googling hasn’t provided successful results. But here is the problem:

This does not work:

function include_a(){
    // Just imagine some complicated code
    if(isset($_SESSION['language'])){
        include 'left_side2.php';
    } else {
        include 'left_side.php';
    }
    // More complicated code to determine which file to include
}

function b() {
    include_a();
    print_r($lang); // Will say that $lang is undefined
}

So essentially, there is an array called $lang in left_side.php and left_side2.php. I want to access it inside b(), but the code setup above will say that $lang is undefined. However, when I copy and paste the exact code in include_a() at the very beginning of b(), it will work fine. But as you can imagine, I do not wish to copy and paste the code in every function that I need it.

How can I alleviate this scope issue and what am I doing wrong?

Answer 1

If the array $lang gets defined inside the include_a() function, it is scoped to that function only, even if that function is called inside b(). To access $lang inside b() you need to call it globally.

This happens because you include 'left_side2.php'; inside the include_a() function. If there are several variables defined inside the includes and you want them to be at global scope, then you will need to define them as such.

Inside the left_side.php, define them as:

$GLOBALS['lang'] = whatever...;

Then in the function that calls them, try this:

function b() {
    include_a();
    print_r($GLOBALS['lang']); // Now $lang should be known.
}