PHP Dynamic Include Help on Index.php?

Question

I need someone to let me know a solution to this issue. I am trying to create an include on my index.php file so when a user clicks a link on my navbar the content on the index.php changes. The code below works great, except when I go to index.php, because it is not part of the array, it calls main.php twice, instead of once. I know this is because of the last portion that says:

    else {
    include('main.php');
    }

However, I need a solution to this because I am not good with php. Here is my full code for the include.

    <?php
    // Place the value from ?page=value in the URL to the variable $page.
    $page = $_GET['id'];
    // Create an array of the only pages allowed.
    $pageArray = array('index','css-pub1','page2','page3','page4','page5','page6');
    // If there is no page set, include the default main page.
    if (!$page) {
    include('main.php');
    }
    // Is $page in the array?
    $inArray = in_array($page, $pageArray);
    // If so, include it, if not, emit error.
    if ($inArray == true) {
    include(''. $page .'.php');
    } 
    else {
    include('main.php');
    }
    ?>

Answer 1

Try to use include_once instead of include:

include_once($page . '.php');
//...
include_once('main.php');

Answer 2

Just remove

if (!$page) {
    include('main.php');
}

and let the else handle main.php

Answer 3

It's because you're trying to grab the wrong $_GET parameter. Should be:

$page = $_GET['page'];

If your comments are accurate.

Answer 4

I have commented the code on the problems and fixes.

<?php
// initilize $page
$page='';
// Place the value from ?page=value in the URL to the variable $page.
if (isset($_GET['id'])){ // check if the page is set
    $page = $_GET['id'];
}
// Create an array of the only pages allowed.
$pageArray = array('index','css-pub1','page2','page3','page4','page5','page6');

/* This section is not needed
// If there is no page set, include the default main page.
if (!$page) {
include('main.php');
}
*/

// Is $page in the array?
$inArray = in_array($page, $pageArray);
// If so, include it, if not, emit error.
if ($inArray == true) {
include(''. $page .'.php');
} 
else {
// If there is no page set, include the default main page.
// this also does the same thing as the commented if loop above
include('main.php');
}
?>