-> file_A.php <?php echo 'Hello there!<br>'; ?> -> file_B.html My name is <b>Mike</b>. -> IncludeExample.php <?php include 'file_A.php'; include '../../file_B.html'; echo "I love PHP!"; ?>
In the above example,Output
Hello there! My name is Mike. I love PHP!
Some of the usage of Include statatements are,
1. Include header's and footer's to pages.
1. Include navigation menu's to pages.
2. Holding variable's that are used across pages
3. Designing layouts for websites
4. Including dynamically generated contents
include_path = string;
include_path = ".:/dir1/dir2";
include_path = ".;c:\dir1\dir2";
-> file_A.php <?php echo 'Hello there!<br>'; ?> -> IncludeExample2.php <html> <head> <body> <?php include 'fileA.php'; ?> </body> </html>
-> file_A.php <?php echo 'Hello there!<br>'; ?> -> IncludeExample3.php <html> <head> <body> <?php include '../fileA.php'; ?> <?php echo "<br>This will still be printed!!" ?> </body> </html>
As the warning message is displayed on the Console (or webpage) this may reveal files name a path details causing an security issue.Output
Warning: include(../fileA.php): failed to open stream: No such file or directory in I:\xampp\htdocs\xampp\Tutorials\IncludeExample3.php on line 5 Warning: include(): Failed opening '../fileA.php' for inclusion include_path='.;I:\xampp\php\PEAR') in I:\xampp\htdocs\xampp\Tutorials\IncludeExample3.php on line 5 This will still be printed!!
include_once should be used when a same file might be included and evaluated more than once during a particular execution of a script. It will help to avoid problems such as function redefinitions, variable value reassignments, etc.
-> file_A.php <?php echo 'Hello there!<br>'; ?> -> IncludeExample.php <?php include_once 'file_A.php'; //file_A.php will be included. include_once 'file_A.php'; //As file_A.php is included //above (using include_once) it wont be included again. echo "I love PHP!"; ?>
Note : "Hello there!" is printed only once!Output
Hello there! I love PHP!