PHP File Inclusion
PHP has two function which can used to include one PHP file into another PHP file before the server executes it.
- The include() function
- The require() function
For the designing purpose in web forms the same header, footer or menu displayed on all web pages of website. Programmer has to design same menu on multiple pages, if changes required in future it will very complicated to open all pages then make change on all pages.
for resolving this problem we use include and require function in php. Just design menu or header in one php page and display same menu on multiple pages using include function. if changes required on menu.php page, it will make effect on all other pages automatically.
The include() function
The include function copy all text of one PHP file into another PHP file that used the include statement.
The include function used when we use same menu or header on multiple pages of a website.
PHP include() syntax:
include ‘ filename’;
PHP include Example
We have a same header for all website pages so create “header.php” file like:
<?php
echo "<h1> Welcomme Meera Academy </h1>";
?>For include header file in all pages , use include statement like:
<html>
<head>
<title>PHP include Example</title>
</head>
<body>
<?php include 'header.php'; ?>
<p>The first page of site</p>
</body>
</html>The output of include() example:
Example
We have same menu on all website pages, create “menu.php” file like:
<?php
echo '<ul><li><a href="home.com">HOME</a></li>
<li><a href="php.com">PHP</a></li>
<li><a href="asp.com">ASP.NET</a></li>
<li><a href="project.com">PROJECTS</a></li></ul>';
?>We use above menu on all web pages. use include statement to display “menu.php” file on all pages.
<html>
<head>
<title>PHP include Example</title>
</head>
<body>
<?php include 'menu.php'; ?>
<p>The first page of site</p>
</body>
</html>The output is :
The PHP require() Function
The require() function copy all the text from one php file into another php file that uses the require() function.
In require() function there is a problem with file then the require() function generate fatal error and stop execution of code.
while the include() function will continue to execute script.
The require() function is better than the include() function, because scripts not to be continue if file has problem or missing.
The above include() function example generate same result for require() function.
Here, we will take an php example to understand difference between require() and include() function.
We try to copy “missing.php” file in to another php file using require() and include() function.
The “missing.php” file does not exists.
For include() function
<html>
<head>
<title>PHP include Example</title>
</head>
<body>
<?php include 'missing.php'; ?>
<p>The first page of site</p>
</body>
</html>The output of include() function is :
The first page of site
The above same example we use require() function incited of include() function.
For require() Function
<html>
<head>
<title>PHP include Example</title>
</head>
<body>
<?php include 'missing.php'; ?>
<p>The first page of site</p>
</body>
</html>The output will be nothing.