If you are developing any application or website, you may always needs to include the external files for several purposes. So “include” function in PHP plays an important role if you want to include any external files. We have already explained all the functions which are being used to include any external files. Mainly there are four functions as mentioned below:
- include() – The include statement in PHP
- include_once() – The include_once statement in PHP
- require() – require statement in PHP
- require_once() – The require_once statement in PHP
So you can go through all the four chapters mentioned above for the complete details if you want to include any external file in your program. All the differences are clearly mentioned about all the four methods.