How can PHP be effectively used as both an OOP language and a template language in web development?

To effectively use PHP as both an OOP language and a template language in web development, you can create separate classes for your business logic and use PHP templates for your presentation layer. This allows you to separate concerns and maintain a clean and organized codebase. You can use PHP's object-oriented features to encapsulate your business logic and use PHP templates like PHP's built-in `include` function or a template engine like Twig to handle your presentation logic.

// Example of using PHP as both an OOP language and a template language

// Class for business logic
class User {
    private $name;

    public function __construct($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

// Instantiate User class
$user = new User('John Doe');

// Include template file for presentation
include 'template.php';
```

In `template.php`:
```php
<!DOCTYPE html>
<html>
<head>
    <title>User Profile</title>
</head>
<body>
    <h1>Welcome, <?php echo $user->getName(); ?></h1>
</body>
</html>