Introduction to include () and require () in php

This article describes in detail the file call tests in php, including include (), require (), include_once (), require_once (), and many other exchange calls, for more information, see.

7.3.1 use of Include, can contain the same file multiple times

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<? Php Include 'demo1. php '; Include 'demo1. php '; Include 'demo1. php '; ?>

 

The output result is as follows:

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E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359 -------------------------------------------------------------------------------- E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359 -------------------------------------------------------------------------------- E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359

 

7.3.2 using include_once is no different from using include, but multiple calls only contain the same file once.

 

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<? Php Include_once 'demo1. php '; Include_once 'demo1. php '; Include_once 'demo1. php '; ?>

 

The result is as follows:

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E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359

 

7.3.3 the require () statement contains and runs the specified file.

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<? Php Require 'demo1. php '; Require 'demo1. php '; Require 'demo1. php '; ?>

The result is as follows:

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E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359 -------------------------------------------------------------------------------- E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359 -------------------------------------------------------------------------------- E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359

 

7.3.4 the require_once () statement contains and runs the specified file during script execution, but does not contain the same file repeatedly.

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<? Php Require_once 'demo1. php '; Require_once 'demo1. php '; Require_once 'demo1. php '; ?>

 

The output result is as follows:

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E10adc3949ba59abbe56e057f20f883e 7c4a8d09ca3762af61e59520943dc26494f8941b 3.14159265359 s

 

7.3.5 differences 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.

 

When calling a non-existent file, Include will give a warning, but will continue to execute the subsequent code.

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<? Php Include 'demo11.php ';   Echo ('this is demo13.php '); ?>

The output result is as follows:

 

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

 

When Require calls a non-existent file, it will give an error and abort code execution.

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<? Php Require 'demo111. php ';   Echo ('this is demo14.php '); ?>

The output result is as follows:

 

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