Symfony interview questions and Answers
Symfony is one of the most widely used PHP frameworks with a set of reusable components and options. Symfony aims to expedite the creation and maintenance of web applications and replace repetitive coding tasks. Though Symfony is known for its low-performance overhead, it gives developers control over the overall configuration. Though most of the Symfony Interview Questions vary from organization to organization, we would still like to put together these related questions and answers that you can expect during the interview.
Development History: Symfony was published as free software in October 2005, and released under the MIT license.
- Sponsored by SensioLabs.
- Inspired by the Spring Framework.
- Symfony ranks 3rd in popularity after Laravel and CodeIgniter.
- It is aimed at building robust, enterprise-level applications.
- Makes use of existing PHP open source projects.
- They are bundled with additional components to help developers test and debug projects.
Most Frequently Asked Symfony interview questions
Here in this article, we will be listing frequently asked Symfony interview questions and Answers with the belief that they will be helpful for you to gain higher marks. Also, to let you know that this article has been written under the guidance of industry professionals and covered all the current competencies.
Symfony is a leading, reliable and one of the most used PHP framework combined with a set of highly featureful and reusable PHP components to create websites, dynamic web applications, web services and microservices. It is an open source framework and supports the MVC design pattern.
Bundles in Symfony are similar to packages or plugins in other CMS or frameworks. In Symfony, bundles provide the developers with the flexibility to use pre-built features consisted of third-party bundles or to create and distribute their own bundles.
Symfony has two types of bundles:
- Application specific bundles
- Reusable bundles
Symfony controller is a PHP function that obtains information from the HTTP request to construct and return an HTTP response. The response can vary and could be an XML document, an HTML page, a redirect, a 404 error, a serialized JSON array, or any other request.
A group of configurations used to run an application is basically described as an Environment in Symfony.
This framework has two default environments:
- Prod: Optimized for executing an application on production
- Dev: Used when an application is developed locally.
Symfony framework supports various user popular web servers. For example, few of the best web servers compatible with Symfony are LAMP, WAMP, XAMP, MAMP, Microsoft IIS, Nginx, and PHP’s built-in web server.
A Symfony controller can do virtually anything inside this framework. From redirecting and forwarding to accessing core services to rendering templates; a controller in Symfony can be used for various basic tasks.
Few crucial innovations that implemented with Symfony2 are as following:
- Use of the Dependency Injection Pattern
- Complete Bundle setup
- Packed as Distributions
- Ease of debugging an application
- Improved security additions
The Symfony routing configuration files are written with YAML, XML and PHP technology. The default routing configuration file in Symfony is: app/config/routing.yml
Serializer is a component present is Symfony that offers developers an option to convert a PHP object into a specific format such as JSON, Binary, XML, etc.
Twing is a templating language present in Symfony. Developers use it to perform sandboxing, automatic HTML escaping, whitespace control, and various other purposes.
Symfony has five cache adapters available inside it. The available cache adapters are as following:
- File system cache adapter
- Array cache adapter
- APCu cache adapter
- PHP files cache adapter
- Redis cache adapter
When an unauthorized individual tries to access the web application, Symfony shows a 403 HTTP status and throws an error page denying the user access request.
Symfony 4.0 is the latest version of the series and requires a server requirement of:
- PHP 5.5.9 or above
- JSON enabled
- Composer
- type enabled
- set of date. timezone
There are four general rules need to be followed to create methods within the controller in Symfony, which are as following:
- Only action methods should be public
- “Action” suffix must be included in action methods
- Controller methods should be short
- A valid response object should be fixed for action methods
Yes, it’s possible to create a Symfony application using composer. The developer needs to run the following command in the console to install Symfony using composer:
composer create-project symphony/framework-standard-edition my_project_name
Symfony2 uses a SessionInterface object set and get method to get and set sessions.
Following syntax can be referred as an example:
public function sessionAction(SessionInterface $session)
{
// store an attribute for reuse during a later user request
$session->set('user_id', 5);
// get the attribute set by another controller in another request
$user_id = $session->get('user_id');
}
In Symfony, developers can get the request parameter by using the following syntax:
$this->container->get('request');$name=$request->query->get('name');
Symfony has following form helper functions for developers:
- Checkbox
- Form_start
- Form_end
- Textarea
- Input_password_tag
Using Symfony has a number of its unique benefits, such as:
- Fast development
- Unlimited user flexibility
- MVC pattern
- The stable and sustainable framework
- Better user control & ease of use
- Expandable
Yes, it’s possible to create a request object in Symfony by developers. Use the
createFromGlobals() methods to simply create the request object.