需要一些PHP帮助

Question

how do i tell this php code that, when there's not a ?page=randompage in the url, it will trow the active to index.php automatically?

<?php
$query = "SELECT pagename, pagetitle FROM pages LIMIT 8"; 
$result = $mysqli->query($query); 
echo "<ul>";
while ($row = $result->fetch_array(MYSQLI_ASSOC)){ 
  echo "<li><a href=\"?page=".$row["pagename"]."\""; 
  if ($_GET['page'] == $row['pagename']) { 
  echo " class=\"active\""; } echo "> ".$row["pagetitle"]." </a></li>";
}
echo "</ul>";
?>

It's beacuse whenever my url looks like this http://localhost/greencph/ it shows a php error, because it does not know which site it is on, it works perfect as long as the url looks like this: http://localhost/greencph/?page=index.php a detailed explanation on how to fix this problem would be appreciated!

Please remember i'm a idiot, explain to me so i understand it. xD

Answer 1

The error is coming because, every time the value of $_GET is not getting set.

So, to deal with it,

get the value of $_GET['page'] in a variable.

So that, if we do not get $_GET , we will assign it a default value, that is index page.

$page = ! empty($_GET['page']) ? $_GET['page'] : 'index'; // set default value.

And change this line:

if ($page == $row['pagename']) {

So, the final modified code should be:

<?php
$query = "SELECT pagename, pagetitle FROM pages LIMIT 8";
$result = $mysqli->query($query);
$page = ! empty($_GET['page']) ? $_GET['page'] : 'index';
echo '<ul>';
while ($row = $result->fetch_array(MYSQLI_ASSOC)) {
    $class = '';
    if ($page == $row['pagename']) {
        $class =  'active';
    }
    echo '<li><a href="?page='.$row["pagename"].'" class="'.$class.'">' . $row["pagetitle"].' </a></li>';
}
echo "</ul>";
?>

Answer 2

Use the $_GET array:

<?php
   if(isset($_GET['page'])) {
       // Your code
       ...
   }
?>

Answer 3

Problem is in this line

if ($_GET['page'] == $row['pagename']) {

You're not checking whether the index 'page' even exists. So, when you try to load the page without any GET parameters $_GET['page'] won't be even set and you'll get an error for accessing unset element.

To fix this simply check

if(isset($_GET['page']) {
    ...your code...
}