Online PHP editor | refs for A24SQ

<?php echo 'bla'; ECHO 'blee'; ecHO 'ho,ho'; echo TRUE; echo true; echo trUE; echo PHP_OS; echo php_OS; var_dump(TRUE,FALSE,NULL); // they have data types and what has data types? variables; not keywords! function true(){ return 'The truth ...'; } function false(){ return 'Do not be false...'; } function null(){ return 't\'is nothing at all...'; } echo true(); echo false(); echo null();