Online PHP editor | output for p1uN3

<?php $primary = 0; echo ($primary || $primary === "0" || $primary === 0) ? 1 : 0; echo "\n\r"; echo ("- " . !empty($primary) ? 1 : 0;) echo "\n\r"; $primary = "0"; echo ($primary || $primary === "0" || $primary === 0) ? 1 : 0; echo "\n\r"; echo ("- " . !empty($primary) ? 1 : 0;) echo "\n\r"; $primary = NULL; echo ($primary || $primary === "0" || $primary === 0) ? 1 : 0; echo "\n\r"; echo ("- " . !empty($primary) ? 1 : 0;) echo "\n\r"; $primary = ''; echo ($primary || $primary === "0" || $primary === 0) ? 1 : 0; echo "\n\r"; echo ("- " . !empty($primary) ? 1 : 0;) echo "\n\r";