<?php
$array = array(
    "foo" => "bar",
    "bar" => "foo",
);

// as of PHP 5.4
$array = [
    "foo" => "bar",
    "bar" => "foo",
];
?>

If these libraries like PHPMailer,  (as fixed in phpList) or other code snippets are going to be ported to FA for use in earlier versions of PHP than v5.4, then we will need to code them back to the earlier simple array() syntax.