Retrieving Subdomain from URL in PHP

Identifying the subdomain within a URL can be a common task in various web applications. This article explores PHP's functionality for extracting the subdomain from a given URL.

Function to Extract Subdomain

PHP doesn't provide a built-in function to retrieve the subdomain. However, there's a simple workaround using the array_shift() and explode() functions:

function getSubdomain($url) {
  // Split the URL into its components
  $parts = explode('.', $url);
  
  // Remove the top-level domain (e.g., "com", "net")
  array_shift($parts);
  
  // Return the first element, which is the subdomain
  return $parts[0];
}

Example Usage

To retrieve the subdomain from a URL, such as "en.example.com," you would use:

$subdomain = getSubdomain('en.example.com'); // "en"

Alternatively, using PHP 5.4 or later, you can simplify the process:

$subdomain = explode('.', 'en.example.com')[0]; // "en"