Laravel interview questions

Laravel interview questions Download Laravel interview questions PDF

Laravel interview questions

One of the most powerful feature of Laravel is its Service Container. It is a powerful tool for resolving class dependencies and performing dependency injection in Laravel.
Dependency injection is a fancy phrase that essentially means class dependencies are “injected” into the class via the constructor or, in some cases, “setter” methods.

Use the enableQueryLog method to enable query log in Laravel


DB::connection()->enableQueryLog(); 
You can get array of the executed queries by using getQueryLog method:
$queries = DB::getQueryLog();

In Laravel, we can use $request->ajax() method to check request is ajax or not.

Example:

      public function saveData(Request $request)
        {
            if($request->ajax()){
                return "Request is of Ajax Type";
            }
            return "Request is of Http type";
        }

In order to install Laravel, make sure your server meets the following requirements:

  • PHP >= 7.1.3
  • OpenSSL PHP Extension
  • PDO PHP Extension
  • Mbstring PHP Extension
  • Tokenizer PHP Extension
  • XML PHP Extension
  • Ctype PHP Extension
  • JSON PHP Extension

Named routing is another amazing feature of Laravel framework. Named routes allow referring to routes when generating redirects or Urls more comfortably.
You can specify named routes by chaining the name method onto the route definition:

Route::get('user/profile', function () {
    //
})->name('profile');

You can specify route names for controller actions:

Route::get('user/profile', 'UserController@showProfile')->name('profile');

Once you have assigned a name to your routes, you may use the route's name when generating URLs or redirects via the global route function:

// Generating URLs...
$url = route('profile');
// Generating Redirects...
return redirect()->route('profile');

In software engineering, dependency injection is a technique whereby one object supplies the dependencies of another object. A dependency is an object that can be used (a service). An injection is the passing of a dependency to a dependent object (a client) that would use it. The service is made part of the client’s state.[1] Passing the service to the client, rather than allowing a client to build or find the service, is the fundamental requirement of the pattern.
https://en.wikipedia.org/wiki/Dependency_injection
You can do dependency injection via Constructor, setter and property injection.

Below are types of relationships supported by Laravel Eloquent ORM.

  • One To One
  • One To Many
  • One To Many (Inverse)
  • Many To Many
  • Has Many Through
  • Polymorphic Relations
  • Many To Many Polymorphic Relations

You can read more about relationships in Laravel Eloquent from here

Migrations are necessary because:

  • Without migrations, database consistency when sharing an app is almost impossible, especially as more and more people collaborate on the web app.
  • Your production database needs to be synced as well.

Lumen is PHP micro-framework that built on Laravel’s top components.It is created by Taylor Otwell. It is perfect option for building Laravel based micro-services and fast REST API’s. It’s one of the fastest micro-frameworks available.
You can install Lumen using composer by running below command

composer create-project --prefer-dist laravel/lumen blog

As the name suggests, Middleware acts as a middleman between request and response. It is a type of filtering mechanism. For example, Laravel includes a middleware that verifies whether the user of the application is authenticated or not. If the user is authenticated, he will be redirected to the home page otherwise, he will be redirected to the login page.

There are two types of Middleware in Laravel.
Global Middleware: will run on every HTTP request of the application.
Route Middleware: will be assigned to a specific route.
Read more about Laravel middlewares

Composer is a tool for managing dependency in PHP. It allows you to declare the libraries on which your project depends on and will manage (install/update) them for you.
Laravel utilizes Composer to manage its dependencies.