Laravel中URL，ACTION，ROUTE区别

Route::get('articles',['uses'=>'ArticlesController@index','as'=>'articles.index']);

<a href="%7B%7B%20url('/articles')%20%7D%7D">链接</a><a href="%7B%7B%20URL::to('/articles')%20%7D%7D">链接</a>

<a href="%7B%7B%20URL::route('articles.index')%20%7D%7D">链接</a><a href="%7B%7B%20route('articles.index')%20%7D%7D">链接</a>

<a href="%7B%7B%20URL::action('ArticlesController@index')%20%7D%7D">链接</a><a href="%7B%7B%20action('ArticlesController@index')%20%7D%7D">链接</a>