Constant

Warning: Constant DOG already defined in /home/herna632/public_html/infost440/assignment3/constant.php on line 9
My dog is called Rex.

Warning: Constant CAT already defined in /home/herna632/public_html/infost440/assignment3/constant.php on line 12
My cat is called Diego.

Constant differ from variables as they can not be changed once they are created.