Introduction to include () and require () in php

This article describes in detail the file call tests in php, including include (), require (), include_once (), and require_once. Include

This article describes in detail the file call tests in php, including include (), require (), include_once (), and require_once.

Use of Include, can contain the same file multiple times,The code is as follows:

2. Include 'demo1. php ';
3. Include 'demo1. php ';
4. Include 'demo1. php ';
5. ?>

The output result is as follows:

1. Same content
2. ----
3. Same content
4. ----
5. Same content

Include_once is similar to include, but multiple calls only contain the same file once.The code is as follows:

2. Include_once 'demo1. php ';
3. Include_once 'demo1. php ';
4. Include_once 'demo1. php ';
5. ?>

The result is as follows:

The require () statement contains and runs the specified file. the code is as follows:

2. Require 'demo1. php ';
3. Require 'demo1. php ';
4. Require 'demo1. php ';
5. ?>

The result is as follows:

1. Same content
2. ----
3. Same content
4. ----
5. Same content

The require_once () statement contains and runs the specified file during script execution, but does not contain the same file repeatedly. the code is as follows:

2. Require_once 'demo1. php ';
3. Require_once 'demo1. php ';
4. Require_once 'demo1. php ';
5. ?>

The output result is as follows:

Difference Between include and require

If there is other code behind Include, when an error occurs in calling include, the subsequent code will continue to be executed, but require will not. Include will give a warning when calling a non-existent file, however, the code is as follows:

2. Include 'demo11.php ';
3. Echo ('this is demo13.php ');
4. ?>

The output result is as follows:

1. Warning: include (demo111.php) [function. include]: failed to open stream: No such file or directory in D: AppServwwwBasic7demo13. php on line 2
2. Warning: include () [function. include]: Failed opening 'demo111. php' for future Sion (include_path = '.; C: php5pear') in D: AppServwwwBasic7demo13. php on line 2
3. This is demo13.php

When Require calls a non-existent file, it will give an error and abort code execution. the code is as follows:

2. Require 'demo111. php ';
3. Echo ('this is demo14.php ');
4. ?>

The output result is as follows:

1. Warning: require (demo111.php) [function. require]: failed to open stream: No such file or directory in D: AppServwwwBasic7demo14. php on line 2
2. Fatal error: require () [function. require]: Failed opening required 'demo111. php' (include_path = '.; C: php5pear') in D: AppServwwwBasic7demo14. php on line 2