Include and require include_ Once and require_ Once difference

1 , There is only one difference between the two , That is the degree of demand for the included documents ,include That is to say, it contains , If the included file does not exist , Then an error will be prompted , But the program will continue to run .

 2,require It means to need , If the included file does not exist or cannot be opened , It will prompt the error , And will terminate the execution of the program .

3, once It means once , that include_once and require_once Indicates that it only contains once , Avoid repeated inclusion .