Explain include(), include_once, require() and require_once?
Include(), include_once, require() and require_once are different functions that often used in PHP coding.
- include(): The include() function is used to insert a php file into the current php file. In execution, if an error occurs, the include() function gives a warning and the script still gets executed.
- include_once(): The include_once() function inserts the php file into the current php file only once. The php file will be called only once and any more calling of that file will be ignored.
- require(): Require() function is similar to include() function. Only difference is that, if an error occurs in execution, it treats it as a fatal error and the script stops execution.
- require_once(): The require_once() includes the php file into the current php file only once.