Define a constant in PHP PHP Add comments Apr 192010 Define a constant in PHP Answer: To define a constant in PHP, you can use define() define ("PI", 3.1415); echo PI; Related posts: Constant in Ruby How to define variable in nginx How to check current PHP version in PHP? Cross platform newline in PHP How to echo string to standard error (stderr)? Leave a Reply Cancel reply Name (required) E-mail (required) URI Your Comment You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>