基于PHP的A/B分流测试问题：HTML页面中PHP调用HTML文件显示空白

Hey there! Let's work through why your PHP code is serving up a blank page instead of rotating your ads. Here are the most likely culprits and fixes to try:

1. PHP isn't running on your server #

If your web host or local environment doesn't have PHP enabled or configured correctly, the server won't process your PHP code—this often leads to a blank page.

Test this quickly: create a file named test.php with this content:

<?php phpinfo(); ?>

If accessing this file in your browser shows nothing but the raw code or a blank screen, you need to enable PHP. For local setups (like XAMPP/WAMP), make sure the Apache/PHP service is running. For shared hosting, reach out to your provider to confirm PHP is enabled for your site.

2. Incorrect file paths for your ad HTML #

The include() function uses relative paths, so ad1.html and ad2.html need to be in the same folder as your PHP file. If they're in a subdirectory (like /ads/), update the path to something like include('./ads/ad1.html').

To debug path issues temporarily enable error reporting at the top of your script—this will show you if PHP can't find the files:

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
if (rand(0,1) == 1) { 
    include ('ad1.html'); 
} else { 
    include ('ad2.html'); 
}
?>

3. Tiny syntax error in your code #

You have an extra semicolon at the end of your else block (}; ?>). While this might not always break everything, it's good practice to fix it:

<?php
if (rand(0,1) == 1) { 
    include ('ad1.html'); 
} else { 
    include ('ad2.html'); 
}
?>

4. Empty or broken ad HTML files #

Double-check that ad1.html and ad2.html actually have valid content. Try accessing them directly in your browser—if they show a blank page too, the issue is with those files, not your PHP logic.

Here's a more robust version of your script that checks if ad files exist before including them, plus debugging tools:

<?php
// Enable error reporting for debugging (remove in production)
error_reporting(E_ALL);
ini_set('display_errors', 1);

// Define your ad file paths
$ad1 = 'ad1.html';
$ad2 = 'ad2.html';

// Randomly pick an ad and include it (with error checks)
if (rand(0, 1) === 1) {
    file_exists($ad1) ? include($ad1) : echo "Error: Ad 1 file missing";
} else {
    file_exists($ad2) ? include($ad2) : echo "Error: Ad 2 file missing";
}
?>

内容的提问来源于stack exchange，提问作者Zoox