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Explanation on PHP Include files

jackloveOriginal: 2018-05-08 09:07:572162browse

include Obtaining files in php plays an important role, so this article will explain its related knowledge in detail.

Server Side Includes (SSI) are used to create functions, headers, footers, or elements that can be reused on multiple pages. The

include (or require) statement takes all text/code/tags present in the specified file and copies them to the file using the include statement.

Include files are useful if you need to reference the same PHP, HTML, or text on multiple pages of your website.

PHP include and require statements

The include or require statements allow you to insert the contents of a PHP file into another PHP file (before the server executes it).

include and require statements are identical, except for the error handling aspect:

require will generate a fatal error (E_COMPILE_ERROR) and stop the script

include only A warning (E_WARNING) is generated and the script continues

So if you wish to continue execution and output results to the user even if the include file is missing, then use include. Otherwise, in frameworks, CMS, or complex PHP application programming, always use require to reference key files to the execution flow. This helps improve application security and integrity in the event that a critical file is accidentally lost.

Including files saves a lot of work. This means you can create standard header, footer or menu files for all pages. Then, when the header needs updating, you simply update the header include file.

Syntax

include &#39;filename&#39;;

require &#39;filename&#39;;

PHP include Example

Suppose we have a standard footer file named "footer.php", just Like this:

628c61d993bdb0dc97ff1be25acac5b2Copyright © 2006-" . date("Y") . " W3School.com.cn94b3e26ee717c64999d7867364b1b4a3";
?>

If you need to reference this footer file in a page, please use the include statement:

<html>
<body>
<h1>欢迎访问我们的首页！</h1>
<p>一段文本。</p>
<p>一段文本。</p>
<?php include &#39;footer.php&#39;;?>
</body>
</html>

Suppose we have a standard named "menu.php" Menu file:

<?php
echo &#39;<a href="/index.asp">首页</a> -
<a href="/html/index.asp">HTML 教程</a> -
<a href="/css/index.asp">CSS 教程</a> -
<a href="/js/index.asp">JavaScript 教程</a> -
<a href="/php/index.asp">PHP 教程</a>&#39;;
?>

All pages in the website use this menu file. Here's how (we use a dc6dce4a544fdca2df29d5ac0ea9906b element so that it can be easily styled via CSS in the future):

<html>
<body>
<div class="menu">
<?php include &#39;menu.php&#39;;?>
</div>
<h1>欢迎访问我的首页！</h1>
<p>Some text.</p>
<p>Some more text.</p>
</body>
</html>

Suppose we have a file called "vars.php" in which we define Some variables:

<?php
$color=&#39;银色的&#39;;
$car=&#39;奔驰轿车&#39;;
?>

Then, if we reference this "vars.php" file, we can use these variables in the calling file:

<html>
<body>
<h1>欢迎访问我的首页！</h1>
<?php
include &#39;vars.php&#39;;
echo "我有一辆" . $color . $car "。";
?>
</body>
</html>

PHP include vs. require

# The ##require statement is also used to reference files in PHP code.

However, there is a huge difference between include and require: if a file is referenced with an include statement and PHP cannot find it, the script will continue executing:

<html>
<body>
<h1>Welcome to my home page!</h1>
<?php
include &#39;noFileExists.php&#39;;
echo "I have a $color $car.";
?>
</body>
</html>

If we use the require statement to accomplish the same In this case, the echo statement will not continue to execute because the script will terminate execution after the require statement returns a serious error:

<html>
<body>
<h1>Welcome to my home page!</h1>
<?php
require &#39;noFileExists.php&#39;;
echo "I have a $color $car.";
?>
</body>
</html>

This article explains in detail the usage of include and the difference with require. Learn more. Please follow the php Chinese website to view the information.

Related recommendations:

Instructions for using PHP EOF (heredoc)

About PHP loops - Detailed explanation of For loops

About the operation of PHP If...Else statement

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