PHP: Including PHP Resource Files

include v.s. require

• include and require only differ in that
  • require -  script will HALT if the file specified is not found
  • include -  script will CONTINUE if the file specified is not found

include

include 'include/init.inc.php';

• include will include the file - even if already included - as an overwrite.
• Previous variable declarations and functions will be replaced.

include_once

include_once 'include/init.inc.php';

• include_once will ONLY include the file if NOT already included.
• if file already included, this statement is basically ignored

require

require 'include/init.inc.php';

• Require will include the file - even if already included - as an overwrite.
• Previous variable declarations and functions will be replaced.

require_once

require_once 'include/init.inc.php';

• require_once will ONLY include the file if NOT already included.
• if file already included, this statement is basically ignored