At one point or another, you may find yourself faced with the need for a route parameter that is consumed before the request hits the controller. You can achieve this using Laravel's routing events and/or middleware, but once you've finished, you'll notice that the controller is receiving the parameter, even though it doesn't need it.

Fortunately, Laravel's Illuminate\Routing\Route object has a method that can help us with this.

/**
 * Unset a parameter on the route if it is set.
 *
 * @param  string  $name
 * @return void
 */
public function forgetParameter($name)
{
    $this->parameters();

    unset($this->parameters[$name]);
}

Once you've extracted your route parameter, simply call the Illuminate\Routing\Route::forgetParameter() method, and it'll be as if it were never there to begin with.

public function handle(Request $request, Closure $next)
{
    // Get the parameter
    $param = $request->route()->parameter('param');

    // Forget the parameter
    $request->route()->forgetParameter('param');

    // Use the parameter
    // Code here...

    return $next($request);
}

When would I use this?

A great example of how this would be used is an application that's localised, using the first segment of the URL path as the locale to use for the request. The URL https://myapp.com/en/about would be represented by the route /{locale}/about, which would have a piece of middleware that extracts the {locale} variable, removes it from the stack, sets the applications' locale, and then continues on with the request.