The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
These constants are used by filter_input() and filter_input_array().
INPUT_POST
POST variables.
INPUT_GET
GET variables.
INPUT_COOKIE
COOKIE variables.
INPUT_ENV
ENV variables.
INPUT_SERVER
SERVER variables.
INPUT_SESSION
SESSION variables. (Removed as of PHP 8.0.0; was not implemented previously)
INPUT_REQUEST
REQUEST variables. (Removed as of PHP 8.0.0; was not implemented previously)