如何使用函数将全局变量包含在另一个函数中？

Question

I have a rather large set of global variables that I want to be able to use within other functions across various files. I know that to use these variables within other functions I need to use the global keyword to include the variable names.

Everything works when I do that, but since there are so many variables, I'd rather create a function that allows me to include the global declaration within the function, with the specific chunk of variables I need being included using a function parameter.

For illustrative purposes, this works:

variables.php (declared before other files are included)

$var1 = 'abc';
$var2 = 'def';
$var3 = 'ghi';

other-function-file.php

function my_function() {
  global $var1, $var2, $var3;
  return $var1 . $var2 . $var3;
}

But this does not work:

variables.php

$var1 = 'abc';
$var2 = 'def';
$var3 = 'ghi';

globals-list-declaration.php

global $var1, $var2, $var3;

globals-include-function.php

function include_globals() {
  include_once('globals-list-declaration.php');
}

other-function-file.php

function my_function() {
  include_globals();
  return $var1 . $var2 . $var3;
}

This is a little simplified, as there multiple variable and global declaration files, and I'll be able to specify which file to include by passing in a parameter to include_globals() in globals-include-function.php.

But for some reason, when I move the hard-typed global $var1, $var2, $var3; to a seperate file and include it in the exact same location (either through include or the include_globals() function decribed above), it ceases to work.

How can I make this work or is it even possible?

Thanks!

Answer 1

From the docs http://php.net/manual/en/function.include.php:

If the include occurs inside a function within the calling file, then all of the code contained in the called file will behave as though it had been defined inside that function

In other words, if can't use this:

function include_globals() {
    include_once('globals-list-declaration.php');
}

Because the definition of globals will only exists inside this function.