Add Header, Footer and navbar files on multiple pages - php

Question

Let says below are my web directories:
From web searching i get to use include or require_once and something similar.But I'm confuse in different directory causes much of directory error.
And my question is, how to include Navbar or Footer or Specific Pages in different directory.
Condition: Same directory as above;

Answer 1

For header,navBar and footer you should used simple
include(page/header.php);
About require and include function Reference
The require() function is identical to include(), except that it
handles errors differently. If an error occurs, the include() function
generates a warning, but the script will continue execution. The
require() generates a fatal error, and the script will stop.
But for image,css files and other js files you should follow these steps
Create config.php file
add this in config.php
define('BASE_URL', 'http://your_website_url');//OR define('BASE_URL', 'localhost')
you can use this path like
<?php
include('config.php');//add this code into top of the page
?>
and finally you can used where you want, like
For Style sheet
<link rel="stylesheet" href="<?php echo BASE_URL; ?>/css/styles.css" />

Answer 2

Create a config.php file in your home directory.
<?php
/* Saves the directory path to base directory as `BASE_DIR`
Example: /var/user1/home/public_html/
'Base directory' is where your homepage/index.php is located */
define('BASE_DIR', dirname(__FILE__) . '/');
?>
now just require this config.php file
<?php
require_once('config.php'); //add this line at top of your pages
// No need to include this inside 'header.php' and 'footer.php'
?>
Now u can include files easily, use it in index.php as follows:
<?php
require_once('config.php');
require(BASE_DIR . 'query/conn.php');
// becomes '/var/user1/home/public_html/query/conn.php'
include(BASE_DIR . 'pages/header.php');
include(BASE_DIR . 'pages/navbar.php');
include(BASE_DIR . 'pages/footer.php');
?>
Note: Similar approach is used by WordPress (learn more)