Array push doesn't work in functions. Even with global

----- The Code -----

<?php
$test = array();
function sup() {
    global $test;
    array_push($test, "0");
}
echo "If it works it will say 0 : ";
echo $test[0];
echo "<br>Now we will push again and it will work but its not in a function: ";
array_push($test, "0");
echo $test[0];
?>

----- The Result -----

If it works it will say 0 :
Now we will push again and it will work but its not in a function: 0