We can use keywords as method names, on PHP7

keywords_method.php

<?php
<?php
class MyClass
{
    public function list()
    {
        echo "list\n";
    }

    public function echo()
    {
        echo "echo\n";
    }
}

echo PHP_VERSION . PHP_EOL;

$obj = new MyClass;
$obj->list();
$obj->echo();

PHP 7.0.2 (cli) (built: Jan 6 2016 14:39:28) ( NTS )

result

list
echo

PHP 5.6.16 (cli) (built: Nov 26 2015 08:01:30)

result

PHP Parse error:  syntax error, unexpected 'list' (T_LIST), expecting identifier (T_STRING) in /vagrant/a.php on line 5