Top Laravel Interview Questions and Answers

After running the composer install in the project directory, the composer will generate the composer.lock file.It will keep a record of all the dependencies and sub-dependencies which is being installed by the composer.json.

We have to use the following artisan commands to enable/disable maintenance mode in Laravel 5.

Enable maintenance mode

php artisan down

Disable maintenance mode

php artisan up

In Laravel, dependency injection is a term used for the activity of injecting components into the user application. It’s a key element of agile architecture. The Laravel service container is a powerful tool that manages all class dependencies and performs dependency injection.

public function __construct(UserRepository $data)
{
    $this->userdata = $data;
}
In this given an example, the UserController needs to retrieve users data from a data source(database). So, we can inject a service that is able to recover all users. In this example, our UserRepository most likely uses Eloquent to get user’s data from the database.

Laravel uses "Blade Template Engine". It is a straightforward and powerful templating engine that is provided with Laravel.

We can create all web pages of our sites to tell Google and other search engines like Bing, Yahoo etc about the organization of our site content. These search engine web crawlers read this file to more intelligently crawl our sites.

Here are the steps that helps you to create real time sitemap.xml file and these steps also helps to create dynamic XML files.

• Firstly we have to create a route for this in your routes/web.php file
  Example
  Route::get('sitemap.xml', 'SitemapController@index')->name('sitemapxml');
• Now you can create SitemapController.php with artisan command php artisan make:controller SitemapController
• Now you can put this code in your controller
  public function index() {
    $page = Page::where('status', '=', 1)->get();
    return response()->view('sitemap_xml', ['page' => $page])->header('Content-Type', 'text/xml');
}
• Now please create a view file in resources/view/sitemap_xml.blade.php file with this code
• Put this code in that created view file
  <?php echo '<?xml version="1.0" encoding="UTF-8"?>'; ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9
http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
@foreach ($page as $post)
<url>
<loc>{{ url($post->page_slug) }}</loc>
<lastmod>{{ $post->updated_at->tz('UTC')->toAtomString() }}</lastmod>
<priority>0.9</priority>
</url>
@endforeach
</urlset>

Laravel provides a variety of aggregate functions such as max, min, count,avg, and sum. We can call any of these functions after constructing our query.

$users = DB::table(‘admin’)->count();
$maxComment = DB::table(‘blogs’)->max('comments');

We can use skip() and take() both methods to limit the number of results in the query. skip() is used to skip the number of results and take() is used to get the number of result from the query.

Vapor in Laravel is a serverless deployment platform auto-scaling and powered by AWS Lambda. It used to manage Laravel Infrastructure with the scalability and simplicity of serverless.

It allows using objects without having to know how these objects are persisted. It is an abstraction of the data layer. It means that our business logic no need to know how data is retrieved. The business logic relies on the repository to get the correct data.

Basically it is used to decouple the data access layers and business logic in our application.

Yes, Laravel supports caching of popular backends such as Memcached and Redis.