Both declare your international variable exterior of operate scope (aka, international scope), or globalize it with the international key phrase.
operate foobar() {
international $aduration;
$aduration = shortcode_atts($default, $atts);
//...
}
To entry a worldwide you declared elsewhere, use the worldwide key phrase once more (globalize the variable), similar to you do with international $submit in your authentic code:
// Assuming `aduration` is asserted international elsewhere, like proven above:
<?php international $aduration; echo $aduration['link']; ?>
In brief, previous any utilization of your international variable with international $myglobal signifies that that is certainly a worldwide variable – no matter whether or not you are declaring it or accessing it. If you happen to declare it inside a operate in features.php with out the international key phrase, it is nothing extra than simply one other native variable, inside that operate.
If declared correctly as a worldwide in features.php, and need to entry it elsewhere – akin to in single.php – globalizing it successfully imports it, so php is aware of to examine the worldwide scope.
