Question 1

What is the correct syntax to declare an enumeration (enum) in PHP 8.1+?

Accepted Answer

In PHP 8.1+, enumerations are declared using the enum keyword followed by the name and possible cases within braces. Enums allow defining a type with a finite set of possible values, which improves type safety and makes code more expressive. Backed enums can have associated string or int values.

Question 2

Which command creates a new Symfony project with all dependencies for a web application?

Accepted Answer

The symfony new --webapp command creates a complete Symfony project with all dependencies needed for a web application (Twig, Doctrine, Security, etc.). The symfony new variant without --webapp creates a minimal project. Composer create-project is a valid alternative but symfony new is recommended as it automatically configures optimal settings.

Question 3

Which PHP attribute should be used to define a route in a Symfony 7 controller?

Accepted Answer

The #[Route] attribute from the Symfony\Component\Routing\Attribute namespace is the recommended method for defining routes in Symfony 7. It replaces Doctrine annotations that required special comments. Native PHP attributes provide better IDE integration and compile-time validation.

Question 4

Which syntax is used to display a variable in a Twig template?

Accepted Answer

The {{ }} (double curly braces) syntax is used to display a variable's content in Twig. This syntax automatically performs HTML escaping to prevent XSS attacks. For control structures, use {% %}, and for comments use {# #}.

Question 5

Which command generates a new Doctrine migration in Symfony?

Accepted Answer

The doctrine:migrations:diff command compares the current database schema with entity metadata and automatically generates a migration containing the differences. This is the recommended method for creating migrations as it avoids manual errors and ensures consistency between code and database.

Question 6

What is API Platform in the Symfony ecosystem?

Accepted Answer

API Platform is an open-source framework dedicated to creating REST and GraphQL APIs. It integrates natively with Symfony and automatically generates OpenAPI documentation, an admin interface, and CRUD endpoints from Doctrine entities. This approach significantly reduces API development time.

Question 7

What is the main role of the Serializer component in Symfony?

Accepted Answer

The Serializer component converts PHP objects to various formats (JSON, XML, CSV, YAML) and vice versa. It plays a central role in REST APIs by transforming entities into structured responses and hydrating objects from incoming requests. The process consists of two steps: normalization (object to array) and encoding (array to final format).

Question 8

In hexagonal architecture, what is the main role of ports?

Accepted Answer

Ports are interfaces that define contracts between the business domain and the outside world. Primary ports (or driving ports) allow external actors to trigger actions in the domain, while secondary ports (or driven ports) allow the domain to interact with external infrastructure like databases or third-party services. This abstraction allows changing implementation without affecting the business domain.

Question 9

What is the main purpose of the Symfony Profiler in the development cycle?

Accepted Answer

The Symfony Profiler is a debugging tool that collects detailed information about each HTTP request: execution time, SQL queries, memory usage, cache, events and more. It helps identify bottlenecks and analyze application behavior without modifying code. Unlike traditional logs, it provides an interactive graphical interface accessible via the Web Debug Toolbar.

Question 10

Which interface must a custom authenticator implement in Symfony 6+?

Accepted Answer

In Symfony 6+, custom authenticators must implement AuthenticatorInterface from the Security HTTP component. This interface defines the methods supports(), authenticate(), onAuthenticationSuccess(), onAuthenticationFailure() and optionally createToken(). It replaces the old Guard system that was used in Symfony 4/5.

Symfony interview questions

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