What is the differene between require(), require_once(), include() and include_once()
All these functions are used to include a file into another file.
require() function includes a file and evaluates it.
require_once() includes the file if and only if is not added before.
require_once() includes the file if and only if is not added before.
require_once() is more recommended than require() function. For example, you want to include a file containing more functions and variable or variable initialization. It is better to use require_once().
require() function produces a fatal error if the file is not found. whereas if you are using include function, It produces warning error.
The difference between include() function and include_once() function is same as that of require() and require_once().
include() function copies all the text from one file to the other file where the include() function is specified.
include() function and require() functions are identical. But the difference in the case of how errors are showing.