What are some common reasons why a PHP script may work locally but not online?

One common reason why a PHP script may work locally but not online is due to differences in server configurations. This can include differences in PHP versions, extensions, or settings between your local environment and the online server. To solve this issue, make sure to check and adjust your script to be compatible with the online server's configuration.

// Example code snippet to check PHP version compatibility
if (version_compare(PHP_VERSION, '7.0.0') < 0) {
    echo "This script requires PHP 7.0 or higher to run.";
    exit;
}