Include :-Include is used to include files more than once in single PHP script.You can include a file as many times you want.
Syntax:- include(“file_name.php”);
Include Once:-Include once include a file only one time in php script.Second attempt to include is ignored.
Syntax:- include_once(“file_name.php”);
Require:-Require is also used to include files more than once in single PHP script.Require generates a Fatal error and halts the script execution,if file is not found on specified location or path.You can require a file as many time you want in a single script.
Syntax:- require(“file_name.php”);
Require Once :-Require once include a file only one time in php script.Second attempt to include is ignored. Require Once also generates a Fatal error and halts the script execution ,if file is not found on specified location or path.
Syntax:- require_once(“file_name.php”);
