include and require in PHP

1. What’s the use?

Server Side Include (SSI) is used to create functions, headers, footers or elements that can be reused on multiple pages. Included files reuse files and save a lot of work.

2. How to use?

include ‘filename’;
Or
require 'filename';

1.php

<code><span><?php</span><span>echo</span><span>"Hello "</span>;
<span>include</span><span>'2.php'</span>;
<span>?></span></code>

2.php

<code><span><span><?php</span><span>echo</span><span>"World."</span>;
<span>?></span></span></code>

You will get 1.php when you access it in the browser (note that 1.php and 2.php are placed at this time (in the same folder): Hello World.

3. What is the difference between include and require?

In terms of error handling:
require will generate a fatal error (E_COMPILE_ERROR) and stop the script
include will only generate a warning (E_WARNING) and the script will continue

Please use this time:
Please use require at this time: when the file is requested by the application.
Use include here: when the file is not required and the application should continue running if the file is not found.