In what scenarios would it be more beneficial to use an existing template engine like Smarty or Twig instead of creating a custom solution in PHP?

Using an existing template engine like Smarty or Twig can be more beneficial when working on a large project with multiple developers, as these engines provide a standardized way to separate logic from presentation. They also offer features like caching, template inheritance, and automatic escaping, which can help improve performance and security. Additionally, using a template engine can make it easier to maintain and update the codebase in the long run.

// Example of using Twig template engine in PHP

// Include the Twig autoloader
require_once 'vendor/autoload.php';

// Specify the path to the templates directory
$loader = new Twig_Loader_Filesystem('templates');

// Instantiate the Twig environment
$twig = new Twig_Environment($loader);

// Render a template
echo $twig->render('index.html', ['name' => 'John Doe']);