PHP が性に合わないなと思う PHP の挙動

kt3k-macbook:php-test $ cat this.php 
<?php
pRiNt_R(aRrAy(true,TRUE,True,tRuE,tRUe));
kt3k-macbook:php-test $ php this.php
Array
(
    [0] => 1
    [1] => 1
    [2] => 1
    [3] => 1
    [4] => 1
)