Карта знаний PHP — huihui-ai:pi-100k, run-101 · think: medium

{"answer": "no", "explanation": "Single-quoted strings only handle \\\\ and \\\\' escapes and do not interpolate variables, while double-quoted strings process all escape sequences and interpolate variables and expressions, so the difference is functional, not just speed."}

{"answer": "yes", "explanation": "The null coalescing operator ?? is syntactic sugar for isset($var) ? $var : default, and like isset(), it does not raise warnings for undefined variables."}

{"answer": "ab", "explanation": "PHP's echo with multiple comma-separated arguments outputs them concatenated with no separator."}

{"answer": "yes", "explanation": "In PHP, print is a language construct that returns the integer 1, allowing it to be used within expressions (unlike echo, which returns nothing)."}

{"answer": "no", "explanation": "The Elvis operator ($a ?: $b) returns the left operand when it is truthy, and the right operand when the left is falsy."}

{"answer": "yes", "explanation": "In PHP, arithmetic operators (+, -) have higher precedence than the string concatenation operator (.), so concatenation is evaluated after addition and subtraction."}

{"answer": "no", "explanation": "The ** operator in PHP is right-associative, so 2 ** 3 ** 2 evaluates as 2 ** (3 ** 2) = 2 ** 9 = 512, not (2 ** 3) ** 2 = 64."}

{"answer": 3, "explanation": "Concatenation (.) has higher precedence than addition (+), so it evaluates ('sum: ' . 2) + 3, which is 'sum: 2' + 3 = 0 + 3 = 3."}

{"answer": "no", "explanation": "With strict comparison (===), arrays are equal only if they have the same key/value pairs in the same order; order matters for === but not for ==."}

{"answer": "no", "explanation": "0 == false uses loose comparison (==) and actually returns true, not false; strict comparison would use ===."}

{"answer": "no", "explanation": "In PHP 8, comparing a non-numeric string to an integer with == returns false, so \"abc\" == 0 evaluates to false (this was a change from PHP 7 where it was true)."}

{"answer": "yes", "explanation": "In PHP, null == 0, null == \"\", and null == false all evaluate to true under loose comparison."}

{"answer": 42, "explanation": "In PHP, casting a string to int reads the leading numeric portion and ignores trailing non-numeric characters, so '42abc' becomes 42."}

{"answer": 10, "explanation": "In PHP, the + operator coerces the numeric string '5' to the integer 5, then performs addition: 5 + 5 = 10."}

{"answer": "no", "explanation": "In PHP, casting false to string results in an empty string \"\", not \"0\"."}

{"answer": "yes", "explanation": "Due to floating-point precision, 0.1 + 0.2 yields 0.30000000000000004, which is not strictly equal (===) to 0.3."}

{"answer": "no", "explanation": "strrev() reverses a string byte-by-byte, which breaks multi-byte UTF-8 characters; you need a multibyte-aware function to correctly reverse UTF-8 strings."}

{"answer": "yes", "explanation": "str_contains('Hello world', 'world') returns true because 'world' is indeed a substring of 'Hello world'."}

{"answer": "no", "explanation": "str_pad() can pad on the right (default), left (STR_PAD_LEFT), or both sides (STR_PAD_BOTH)."}

{"answer": "no", "explanation": "By default, trim() strips spaces, tabs, newlines, carriage returns, null bytes, and vertical tabs (\" \\t\\n\\r\\0\\x0B\"), not just spaces."}

{"answer": 6, "explanation": "In UTF-8, 'é' is 2 bytes, while 'h', 'l', 'l', 'o' are each 1 byte, totaling 6 bytes."}

{"answer": "def", "explanation": "substr with a negative start position counts from the end of the string, so -3 on 'abcdef' starts at 'd' and returns the remaining substring 'def'."}

{"answer": "no", "explanation": "ucfirst() returns a new string with the first character uppercased; it does not modify the original string in place."}

{"answer": "yes", "explanation": "Heredoc (<<<EOT) supports variable interpolation, while nowdoc (<<<'EOT') with quoted delimiter treats the content as a plain string, so no interpolation occurs."}

{"answer": "no", "explanation": "PHP's sort() function reindexes array keys numerically after sorting, so key-to-value associations are not preserved (use asort() for that)."}

{"answer": "yes", "explanation": "In PHP, string keys that represent valid integers (like '5') are automatically cast to integer keys when used in arrays."}

{"answer": "no", "explanation": "in_array() defaults to loose comparison (==); strict comparison requires explicitly passing true as the third argument."}

{"answer": "yes", "explanation": "Without a callback, array_filter() removes all elements that evaluate to false (i.e., falsy values like 0, '', null, false, '0', and empty arrays)."}

{"answer": "no", "explanation": "By default, the $preserve_keys parameter of array_slice() is false, so numeric keys are reindexed starting from 0."}

{"answer": "[20, 30]", "explanation": "array_slice starts at index 1 (value 20) and takes 2 elements, returning [20, 30]."}

{"answer": 2, "explanation": "The + operator keeps left-hand values for duplicate string keys, so the result is ['a' => 1, 'b' => 2], which has 2 elements."}

{"answer": "yes", "explanation": "PHP 8.1 introduced support for the spread operator with arrays that have string keys; previously it only worked with integer keys."}

{"answer": "no", "explanation": "In PHP 8.0+, named arguments and argument unpacking (...$args) can be combined in the same function call, e.g. foo(a: 1, ...$args)."}

{"answer": "no", "explanation": "In PHP, an anonymous function (closure) without the 'use' keyword does not automatically have access to variables from the enclosing scope; you must explicitly import them with 'use'."}

{"answer": 3, "explanation": "func_num_args() returns the total number of arguments actually passed to the function call, which is 3 (1, 2, 3), regardless of how many are declared in the signature."}

{"answer": "no", "explanation": "An arrow function (fn) body must be a single expression after '=>', not multiple expressions in curly braces; that is the syntax of a regular anonymous function (closure)."}

{"answer": "no", "explanation": "PHP arrow functions (fn) automatically capture surrounding variables by value at creation time, not by reference; reference capture requires an explicit closure with use (&$var)."}

{"answer": "yes", "explanation": "In PHP, declaring a closure with the 'static' keyword prevents it from implicitly capturing $this from the enclosing scope."}

{"answer": 5, "explanation": "The 'use ($x)' captures $x by value (not by reference), so the closure retains the original value of 5 regardless of the later reassignment to 7."}

{"answer": "yes", "explanation": "In weak typing mode (the default), PHP will coerce the numeric string \"5\" to the integer 5 when it is passed to an int-typed parameter."}

{"answer": "yes", "explanation": "Constructor property promotion was introduced in PHP 8.0, allowing visibility modifiers on constructor parameters to auto-declare and assign properties."}

{"answer": "final", "explanation": "In PHP, the 'final' keyword before a method declaration prevents subclasses from overriding that method."}

{"answer": "yes", "explanation": "In PHP, a method declared with the final keyword cannot be overridden in a subclass; attempting to do so results in a fatal error."}

{"answer": "no", "explanation": "In PHP, private properties are accessible only within the class that declares them, not in subclasses; protected visibility is needed for subclass access."}

{"answer": "class@anonymous", "explanation": "In PHP, an anonymous class gets a generated name like 'class@anonymous' followed by a NUL byte and additional identifier; the part before the NUL byte is 'class@anonymous'."}

{"answer": "yes", "explanation": "In PHP, private methods are hidden from child classes, so a child can freely redeclare a method with the same name and any visibility without violating the inheritance contract."}

{"answer": "no", "explanation": "__get() is called not only for non-existent properties but also for inaccessible (protected or private) properties accessed from outside the class."}

{"answer": "Error", "explanation": "Reassigning a readonly property in PHP throws a \\readonlyproperty, which is a subclass of \\Error, not \\Exception."}

{"answer": "yes", "explanation": "PHP interfaces can declare constants, which are implicitly public and final."}

{"answer": "instanceof", "explanation": "The instanceof operator in PHP checks whether an object is an instance of a specific class or implements a specific interface."}

{"answer": "yes", "explanation": "In PHP, an interface can declare static methods, and the implementing class must provide the corresponding static method implementation."}

{"answer": "no", "explanation": "PHP's instanceof operator checks both class inheritance and implemented interfaces, so it returns true if the object's class implements the given interface."}

{"answer": "no", "explanation": "In PHP, interface methods are declarations only and cannot have a body or default implementation, whereas trait methods can provide full implementations."}

{"answer": "yes", "explanation": "In PHP, abstract methods in an abstract class can have public, protected, or (since PHP 7.1) private visibility; protected is a common and valid choice."}

{"answer": 3, "explanation": "Foo::cases() returns an array of all defined cases, and there are exactly 3 cases: A, B, and C."}

{"answer": "yes", "explanation": "PHP traits can declare constants, which are then accessible through any class that uses the trait."}

{"answer": "yes", "explanation": "In PHP 7+, both the Exception class and the Error class implement the Throwable interface, making it their common ancestor."}

{"answer": "no", "explanation": "TypeError extends Error (not Exception); both Exception and Error are separate classes that implement Throwable, so catch(Exception) does not catch TypeError."}

{"answer": "no", "explanation": "The @ operator suppresses error reporting (warnings, notices, etc.) but does not prevent exceptions from being thrown or propagating."}

{"answer": "DivisionByZeroError", "explanation": "In PHP, intdiv(5, 0) throws a DivisionByZeroError, which is a built-in exception class extending ArithmeticError."}

{"answer": "no", "explanation": "The finally block in PHP executes regardless of whether an exception was thrown or caught; it runs even when the try block completes normally without any exception."}

{"answer": "no", "explanation": "An exception thrown in a finally block replaces (masks) any exception from the try block or, if the try block completed normally, becomes the propagated exception, so it does affect the outcome."}

{"answer": "yes", "explanation": "In PHP, casting any object to bool returns true unless the class defines a __bool__() magic method; Exception does not, so (bool) new Exception('x') is true."}

{"answer": "yes", "explanation": "Shutdown functions registered with register_shutdown_function() are executed when the script terminates, including when exit/die is called."}

{"answer": "no", "explanation": "The use statement is a compile-time aliasing directive that only maps a shorter name to a fully qualified class name; the class file is actually loaded later (e.g., via the autoloader) when the class is first instantiated or referenced at runtime."}

{"answer": "function", "explanation": "In PHP, to import a function you use the syntax 'use function Namespace\\functionName;', while 'use const' is for importing constants."}

{"answer": "src/Controller/Api/UserController.php", "explanation": "PSR-4 strips the 'App\\' prefix, converts the remaining namespace separators to directory slashes, and appends .php to get the file path under the src/ base directory."}

{"answer": "yes", "explanation": "Composer's vendor/autoload.php ultimately calls spl_autoload_register() to register its autoloader class with PHP's SPL autoloading mechanism."}

{"answer": "yes", "explanation": "__NAMESPACE__ is a PHP magic constant that returns the name of the current namespace (or an empty string in the global namespace)."}

{"answer": "no", "explanation": "An unqualified class name in a new expression is resolved relative to the current namespace, not the global root; only a leading backslash forces resolution from the global root."}

{"answer": "yes", "explanation": "PSR-4 strips the prefix 'App\\' and maps the remaining namespace segments 'Model\\User' to the path 'Model/User.php' under the base directory 'src/', giving 'src/Model/User.php'."}

{"answer": "yes", "explanation": "PHP allows a use statement inside a function body, and the alias applies only within that function's scope."}

{"answer": "yes", "explanation": "In PHP, arrays are value types; assignment and function parameters create a copy (via copy-on-write) unless the reference operator & is explicitly used."}

{"answer": 2, "explanation": "PHP arrays use copy-on-value assignment, so appending to $b does not modify $a; count($a) remains 2."}

{"answer": "yes", "explanation": "In PHP, variables have function scope by default, so global variables must be accessed via the `global` keyword, the `$GLOBALS` superglobal, or by being passed as parameters."}

{"answer": "no", "explanation": "unset($GLOBALS['x']) removes the variable from the global scope entirely; it is not limited to the current function."}

{"answer": 6, "explanation": "The function increments $x by reference, so $n becomes 6 after the call."}

{"answer": "yes", "explanation": "In PHP 5+, foreach by value does not make a separate copy of the array; it uses the array's internal structure directly, so modifications (unset, assignment, adding elements) made inside the loop are immediately visible to the ongoing iteration."}

{"answer": "no", "explanation": "A static property belongs to the class itself and is shared among all instances, so changes made through one object are visible in all others."}

{"answer": "no", "explanation": "In PHP, boolean array keys are cast to integers: true becomes 1 and false becomes 0, so the key is stored as an int, not a bool."}

{"answer": "yes", "explanation": "Since PHP 7.0, a generator can return a value, and it is retrievable via the Generator::getReturn() method after the generator is exhausted."}

{"answer": "no", "explanation": "Generators in PHP are one-time iterators; once fully consumed, rewind() cannot restart them—you must invoke the generator function again to get a fresh instance."}

{"answer": "yes", "explanation": "In PHP, yield from delegates iteration to another generator or Traversable, yielding its values as if they were produced by the current generator."}

{"answer": "Generator", "explanation": "Calling a generator function returns an instance of the Generator class, so get_class() returns the string 'Generator'."}

{"answer": 3, "explanation": "The generator yields 3 elements (1, 2, 3), iterator_to_array converts it to an array of 3 elements, and count returns 3."}

{"answer": "no", "explanation": "SplStack implements a LIFO (Last In, First Out) stack, not a FIFO queue; SplQueue is the one that implements FIFO."}

{"answer": "yes", "explanation": "ArrayIterator is a built-in PHP class that wraps an array and implements the Iterator interface, allowing traversal via methods like current(), next(), key(), valid(), and rewind()."}

{"answer": "no", "explanation": "ArrayObject implements the Iterator interface, so it can be traversed with foreach."}

{"answer": "yes", "explanation": "password_hash() automatically generates a random salt internally and embeds it in the resulting hash string; there is no separate salt parameter to pass."}

{"answer": "no", "explanation": "In PHP 8, PASSWORD_DEFAULT is PASSWORD_BCRYPT, not MD5 with a salt."}

{"answer": "yes", "explanation": "password_verify() returns true when the plaintext password matches the given hash, which it does here since both use 'secret'."}

{"answer": "no", "explanation": "strip_tags() only removes HTML and PHP tags from a string; SQL injection is prevented by prepared statements or proper escaping of SQL special characters, not by stripping HTML tags."}

{"answer": "yes", "explanation": "session_regenerate_id() replaces the current session ID with a new one, which invalidates any previously known session ID an attacker may have set, thereby preventing session fixation attacks (commonly applied at login)."}

{"answer": "php_sapi_name()", "explanation": "The built-in function php_sapi_name() returns the name of the current SAPI (Server API) interface, such as 'cli', 'apache2', or 'fpm-fcgi'."}

{"answer": "yes", "explanation": "session_destroy() removes the session data stored on the server, but the session cookie in the browser must be explicitly deleted (e.g., via setcookie with a past expiration) to be removed."}

{"answer": "no", "explanation": "The $_SESSION array is only populated with session data after session_start() is called; without it, it remains empty."}

{"answer": "no", "explanation": "array_find() is not a built-in PHP function; PHP provides array_filter(), array_search(), and array_map() instead."}

{"answer": "yes", "explanation": "PHP 8.4 introduced property hooks, allowing custom get/set logic to be declared directly within a property definition."}

{"answer": "yes", "explanation": "Asymmetric visibility (e.g., public private(set) string $name) was indeed introduced as a new feature in PHP 8.4."}

{"answer": "8.4", "explanation": "The #[\\NoDiscard] attribute was introduced in PHP 8.4 to allow marking function return values as required to be used."}

{"answer": "no", "explanation": "PHP has never introduced a |> pipe operator; it has | (bitwise OR) and || (logical OR) but no pipe operator as of any released version."}

{"answer": "no", "explanation": "The clone-with syntax clone($obj, ['x' => 1]) has not appeared in any released PHP version; the standard syntax remains clone $obj with no second argument for property overrides."}

{"answer": "8.4", "explanation": "The array_first() and array_last() functions were introduced in PHP 8.4 as part of a new set of high-level array functions."}

{"answer": 9.0, "explanation": "The RFC Partial Function Application v2 was adopted for PHP 9.0."}

{"answer": "8.4", "explanation": "The clamp() function was introduced in PHP 8.4 as part of the RFC clamp_v2, released in November 2024."}

{"answer": "no", "explanation": "There is no widely recognized 'Context Managers v2' RFC that has been adopted into PHP; the feature does not appear in any released PHP version up to the stated date."}

{"answer": "yes", "explanation": "The RFC for Bound-Erased Generic Types (generics) in PHP was voted down/declined in 2026, continuing PHP's pattern of rejecting full generics proposals."}

{"answer": "no", "explanation": "As of the given date, no RFC has been accepted to make the Zend Thread-Safe (ZTS) multithreading build the default in PHP; NTS remains the default build variant."}

{"answer": "yes", "explanation": "PHP 8.5 still does not include native generics (parameterized types); no such feature has been adopted in any PHP release up to and including 8.5."}

{"answer": "yes", "explanation": "PHP releases new major versions in November; 8.5 was released in November 2025, so as of 2026-11-07 it is still the latest stable, with 8.6 GA scheduled for 2026-11-19."}

{"answer": "yes", "explanation": "PHP 6 was a planned major revision that never reached a stable release; PHP 7.0 (December 2015) was the next major version after PHP 5.6."}

{"answer": "no", "explanation": "The RFC proposing a #[\\Deprecated] attribute was not accepted into PHP core; it did not reach the required approval threshold."}

{"answer": "yes", "explanation": "In clean and onion architecture, the dependency rule mandates that inner (domain) layers must not depend on outer layers; all dependencies point inward toward the core."}

{"answer": "yes", "explanation": "In clean/layered PHP architecture, domain entities should be pure PHP objects that depend only on the language and standard library, not on framework or ORM libraries like Doctrine or Symfony."}

{"answer": "no", "explanation": "Controllers and Twig templates belong to the presentation (interface) layer; they call use cases, but the business-logic layer is the use cases/services themselves, not the components that invoke them."}

{"answer": "Entity", "explanation": "In onion architecture, the innermost layer at the very center is the Entity (Domain) layer, representing the core business objects."}

{"answer": "yes", "explanation": "Tools like deptrac (Dependency Tracker) are static analysis tools that can be configured to enforce layer dependency rules and fail the build when a forbidden cross-layer call is detected."}

{"answer": "no", "explanation": "A use case (interactor) should be decoupled from infrastructure; accepting an HTTP request or EntityManager couples it to specific framework/ORM details, violating clean/hexagonal architecture principles."}

{"answer": "Repository", "explanation": "In Domain-Driven Design, a Repository provides a collection-like interface for aggregates/entities while abstracting the underlying storage mechanism behind a common interface."}

{"answer": "yes", "explanation": "In Clean Architecture, the database is an infrastructure concern implemented at the outermost layer; the domain and use cases depend only on abstractions (e.g., a Repository interface), so switching PostgreSQL to another DB requires changes only in that outer layer."}

{"answer": "no", "explanation": "An aggregate in DDD is a domain-level consistency boundary around a cluster of related objects, not a database table; it is a conceptual grouping for business logic, while a table is merely a persistence detail."}

{"answer": "yes", "explanation": "A Value Object is defined by immutability and value-based equality (comparing field values), rather than identity-based equality (reference comparison)."}

{"answer": "Aggregate Root", "explanation": "In Domain-Driven Design, the Aggregate Root is the single entry point of an aggregate through which all external modifications must be made."}

{"answer": "yes", "explanation": "In DDD, a repository is defined per aggregate root, not per individual entity; entities within the aggregate are accessed through the root."}

{"answer": "yes", "explanation": "In Domain-Driven Design, ubiquitous language is a shared language between developers and domain experts that is used consistently in the model, code, and discussions."}

{"answer": "domain", "explanation": "In model theory, the domain (or universe of discourse) is the boundary within which a model consistently interprets the language's symbols, while outside it the same terms can be assigned different meanings in other models."}

{"answer": "no", "explanation": "DDD recommends a rich domain model where business logic is encapsulated within domain objects, not an anemic model with logic pushed into services."}

{"answer": "yes", "explanation": "In Domain-Driven Design, each Bounded Context defines its own model where the same universal concept (e.g., 'Customer') is represented by a different class tailored to that context's specific meaning."}

{"answer": "yes", "explanation": "Symfony's DI container does not pre-instantiate services; they are only constructed the first time they are requested or injected."}

{"answer": "debug:router", "explanation": "The Symfony console command 'bin/console debug:router' lists all registered routes."}

{"answer": "no", "explanation": "Symfony autowiring automatically resolves dependencies based on type hints, so you do not need to manually declare every service in services.yaml."}

{"answer": "yes", "explanation": "Twig compiles templates into PHP classes (extending Twig\\Template) and stores them in a cache directory to avoid recompilation on subsequent requests."}

{"answer": "yes", "explanation": "In the Symfony dev environment the DI container is compiled once and cached; it is only recompiled when tracked files (service configs, etc.) change, not on every request."}

{"answer": "APP_ENV", "explanation": "Since Symfony 5.1, the APP_ENV environment variable (dev, prod, test) selects the active Symfony environment."}

{"answer": "no", "explanation": "Symfony's router calls the controller method from outside the class, so the method must be public; a private method would be inaccessible and throw an error."}

{"answer": "no", "explanation": "Both listeners and subscribers are dispatched based on their assigned priority value, not on whether they are a listener or a subscriber; a high-priority listener is called before a low-priority subscriber."}

{"answer": "yes", "explanation": "Symfony 6.0 removed the legacy Guard authentication system, making the AuthenticatorInterface-based system the standard for handling authentication."}

{"answer": "IsGranted", "explanation": "The #[IsGranted] attribute in Symfony checks a role or permission on a controller action and returns a 403 Forbidden if the user lacks the required grant."}

{"answer": "yes", "explanation": "Symfony Voters (AccessVoter) are the built-in mechanism for object-level access control, and isGranted('EDIT', $post) is the correct usage to check a permission on a specific object."}

{"answer": "yes", "explanation": "Symfony 7 removed the doctrine/annotations reader, so the old @Assert\\NotBlank annotation syntax is no longer supported; PHP attributes (#[Assert\\NotBlank]) are the standard in-code declaration method."}

{"answer": "yes", "explanation": "Symfony forms have CSRF protection enabled by default since Symfony 2.3; a token is automatically generated and validated on submission unless explicitly disabled."}

{"answer": "yes", "explanation": "Symfony's form validation is always performed server-side using the Validator component, regardless of whether client-side HTML5 validation has already passed."}

{"answer": "php bin/console maker:form", "explanation": "The Symfony MakerBundle command 'maker:form' generates a FormType class."}

{"answer": "no", "explanation": "Symfony stores the authenticated user's identifier (e.g., user ID or username) in the session, not the password; the password itself is hashed and stored in the database."}

{"answer": "yes", "explanation": "Symfony Flex convention places bundle/topic-specific configuration in config/packages/, one YAML file per bundle (e.g. framework.yaml, doctrine.yaml)."}

{"answer": "yes", "explanation": "This is a standard PHP best practice (e.g., Symfony) where .env holds safe dev defaults committed to the repo, and .env.local holds real secrets that are git-ignored."}

{"answer": "debug:container", "explanation": "The Symfony command 'debug:container' lists all registered services and their aliases in the service container."}

{"answer": "yes", "explanation": "Symfony's Container class provides setParameter() which can be called at runtime (e.g., in a controller) to modify a parameter value, as long as the container is not frozen (it is frozen in production but not in dev mode)."}

{"answer": "no", "explanation": "Since Symfony 4, services are private by default; you must explicitly set public: true to fetch them directly from the container."}

{"answer": "no", "explanation": "Bundles can work without a config file in config/packages; they can rely on default values defined in their DependencyInjection Configuration class, and some bundles require no configuration at all."}

{"answer": "yes", "explanation": "Symfony uses the %env(VAR_NAME)% syntax in services.yaml and other configuration files to inject environment variable values into service definitions."}

{"answer": "APP_DEBUG", "explanation": "The APP_DEBUG environment variable (set to 1 or true) enables Symfony's debug mode, which activates the profiler, detailed error pages, and Twig debugging."}

{"answer": "no", "explanation": "Symfony Messenger supports multiple handlers for a single message; all matching handlers are invoked sequentially by the HandlingMessagesMiddleware."}

{"answer": "no", "explanation": "The sync transport dispatches the message directly to handlers in the same process without queuing; it does not involve a worker."}

{"answer": "messenger:consume", "explanation": "In Symfony Messenger, the console command 'messenger:consume' starts a worker process that listens to and processes messages from a specified transport queue."}

{"answer": "no", "explanation": "In Symfony Messenger, the retry strategy (retry_strategy) is configured per message bus (or per message via attributes), not per transport."}

{"answer": "yes", "explanation": "By default, Symfony Messenger uses the Serializer component which encodes messages to JSON for transport."}

{"answer": "yes", "explanation": "Symfony Scheduler (introduced in Symfony 7.1) defines recurring tasks that produce messages which are dispatched through the Messenger component for execution."}

{"answer": "doctrine", "explanation": "Symfony Messenger's 'doctrine' transport persists messages into database tables using Doctrine DBAL/ORM."}

{"answer": "yes", "explanation": "Symfony Messenger allows you to add custom middleware to the bus pipeline and control their position relative to built-in middleware via service tags and ordering."}

{"answer": "yes", "explanation": "Symfony follows a release cycle where major versions (e.g., 6.0, 7.0) are introduced roughly every two years in November, while minor versions (e.g., 6.1, 6.2) are released every six months (May and November)."}

{"answer": "8.4", "explanation": "Symfony 8 requires a minimum PHP version of 8.4."}

{"answer": "no", "explanation": "Symfony 7.0 removed support for docblock annotations in favor of native PHP 8 attributes."}

{"answer": "yes", "explanation": "Symfony's AssetMapper uses importmap.php as its configuration and processes CSS/JS natively (via esbuild/Lightning CSS binaries) without requiring Node.js or Webpack."}

{"answer": "no", "explanation": "Symfony 6.4 is actually an LTS (Long-Term Support) release, supported until November 2027, following Symfony's pattern of designating x.4 releases as LTS."}

{"answer": "yes", "explanation": "Symfony's deprecation policy requires that a deprecated feature remains functional for at least two major versions after its deprecation, so deprecations introduced in the previous major branch still work in the next one."}

{"answer": "yes", "explanation": "Each Symfony major release includes an UPGRADE file (e.g., UPGRADE-7.0) documenting breaking changes and migration notes."}

{"answer": "AssetMapper", "explanation": "Symfony's AssetMapper component (introduced in Symfony 6.4/7.0) manages frontend assets and importmaps natively without requiring Node.js or Webpack."}

{"answer": "yes", "explanation": "Following Symfony's standard release cycle (minor versions every ~6 months), Symfony 8.2 is expected to be released in November 2026, which by 2026-11-07 would have already been released."}

{"answer": "no", "explanation": "Following Symfony's six-month release cycle, Symfony 8.1 (not 8.2) is scheduled for November 2026; Symfony 8.2 would come in May 2027."}

{"answer": "8.2", "explanation": "The next minor version after Symfony 8.1 is 8.2."}

{"answer": "no", "explanation": "Symfony 8.2 is a minor release (8.x line), not a major release; major releases follow the X.0 pattern and introduce breaking changes, while minor releases only add features without breaking existing APIs."}

{"answer": "yes", "explanation": "PHP guarantees backward compatibility within the same major version, so minor updates like 8.1 to 8.2 should not break existing code."}

{"answer": "8.4", "explanation": "Following Symfony's consistent release pattern of five minor versions per major branch (e.g., 6.0–6.4, 7.0–7.4), the last minor version of the 8.x branch before 9.0 is 8.4."}

{"answer": "no", "explanation": "Symfony 8.x is expected to require PHP 8.4 as its minimum version, not PHP 8.5; the minimum PHP requirement is typically set at the start of the major cycle and remains consistent across minor versions."}

{"answer": "yes", "explanation": "Symfony's deprecation policy guarantees that deprecations introduced in a major version (8.x) remain for the entire lifetime of that branch and are only removed in the next major version (9.0)."}

{"answer": "no", "explanation": "Twig's {{ }} allows only Twig expressions (variables, filters, registered functions, method calls on objects), not arbitrary PHP code like phpinfo() or full PHP statements."}

{"answer": "yes", "explanation": "Twig has auto-escaping enabled by default (using the 'html' strategy), so variables printed with {{ }} are HTML-escaped automatically to prevent XSS vulnerabilities."}

{"answer": "yes", "explanation": "The Twig |e (escape) filter defaults to the 'html' strategy, escaping characters like <, >, &, \", and ' for safe HTML output."}

{"answer": "number_format", "explanation": "The twig/intl-extra package provides the number_format filter, which formats a number according to a specified locale."}

{"answer": "yes", "explanation": "In Twig, the |raw filter marks a value as safe, preventing it from being auto-escaped during output."}

{"answer": "yes", "explanation": "In Twig, {{ }} is used for outputting expression values, while {% %} is used for executing tags such as conditions, loops, and set statements."}

{"answer": "no", "explanation": "Twig allows declaring variables inside templates using the {% set %} tag, so values do not only come from the controller."}

{"answer": "dump", "explanation": "The Twig function dump() outputs the debug structure of a variable such as an array or object."}

{"answer": "yes", "explanation": "Bootstrap is a front-end CSS/JS framework providing pre-built UI components (grid, modals, navbars), not a Single Page Application framework like Angular, React, or Vue."}

{"answer": "container", "explanation": "The .container class in Bootstrap provides a responsive, centered container with a fixed maximum width that changes at each breakpoint (e.g., 540px, 720px, 960px, 1140px, 1320px)."}

{"answer": "no", "explanation": "The Bootstrap grid splits a row into 12 columns, not 16, and modern versions (v4+) use Flexbox rather than CSS floats."}

{"answer": "yes", "explanation": "Bootstrap 5 defines exactly five named breakpoint infixes: sm (576px), md (768px), lg (992px), xl (1200px), and xxl (1400px)."}

{"answer": "yes", "explanation": "In Bootstrap, utilities like .mt-3 or .px-2 reference a spacing scale ($spacers) whose values are all defined as multiples (including fractional multiples) of the $spacer variable (default 1rem)."}

{"answer": "data-bs-toggle", "explanation": "In Bootstrap 5, the data-bs-toggle attribute is used to enable interactive components such as dropdowns, tooltips, popovers, and collapse elements."}

{"answer": "yes", "explanation": "Bootstrap 5 removed the jQuery dependency and its interactive components (modals, tooltips, dropdowns, etc.) are built with vanilla JavaScript and Popper.js."}

{"answer": "no", "explanation": "In Bootstrap 5.3, dark mode is enabled with the data-bs-theme=\"dark\" attribute on the <html> element, not a .dark class."}

{"answer": "no", "explanation": "Doctrine ORM does not automatically create tables at runtime; you must explicitly run schema tools or migrations to create the database structure."}

{"answer": "persist", "explanation": "EntityManager::persist() marks a new entity as managed in the persistence context without issuing SQL; the INSERT is only generated on flush()."}

{"answer": "no", "explanation": "EntityManager::merge() does exist in Doctrine ORM 3, but it does not make the passed object managed; it returns a new managed copy while the original remains detached."}

{"answer": "yes", "explanation": "DQL (Doctrine Query Language) operates at the ORM level, referencing entity class names and their mapped fields rather than raw database tables and columns."}

{"answer": "null", "explanation": "Doctrine's EntityRepository::find() returns null when no entity matching the given ID is found."}

{"answer": "no", "explanation": "DoctrineBundle does not automatically call flush() at the end of a request; developers must explicitly invoke $em->flush() to persist pending changes to the database."}

{"answer": "yes", "explanation": "In Doctrine ORM, the Unit of Work performs dirty-checking on all managed entities during flush(), so modifying a property on an already-managed entity is automatically detected and committed without needing an explicit persist() call."}

{"answer": "no", "explanation": "In Doctrine ORM, remove() only marks the entity as scheduled for deletion in the UnitOfWork; the actual SQL DELETE is issued when flush() is called."}

{"answer": "no", "explanation": "MVCC's whole purpose is the opposite: readers do not block writers and writers do not block readers, because each transaction sees a consistent snapshot of the data."}

{"answer": "EXPLAIN", "explanation": "The EXPLAIN SQL command displays the query execution plan (how the database will execute the query) without actually running the query."}

{"answer": "no", "explanation": "While both provide auto-incrementing values, SERIAL is syntactic sugar that creates a separate sequence + DEFAULT, whereas GENERATED AS IDENTITY is a SQL-standard column attribute with different override semantics (OVERRIDING SYSTEM VALUE), tighter coupling to the column, and different alter/drop behavior."}

{"answer": "no", "explanation": "By default, PostgreSQL treats NULL values as distinct from each other in UNIQUE constraints, so multiple rows can have NULL in that column."}

{"answer": "string_agg", "explanation": "PostgreSQL's string_agg() aggregate function concatenates strings with a specified separator."}

{"answer": "no", "explanation": "Plain VACUUM only marks dead-tuple space as reusable within the table; it is VACUUM FULL that rewrites the table and returns space to the OS."}

{"answer": "PARTITION BY", "explanation": "The PARTITION BY clause in a window function definition divides rows into groups over which the window function is computed."}

{"answer": "no", "explanation": "READ COMMITTED only protects against dirty reads; non-repeatable reads are prevented at the REPEATABLE READ level or higher."}

{"answer": "yes", "explanation": "PostgreSQL operates in autocommit mode by default, meaning each individual SQL statement is automatically committed as its own implicit transaction unless explicitly wrapped in a BEGIN...COMMIT block."}

{"answer": "COMMIT", "explanation": "The COMMIT SQL command ends a transaction and permanently saves all changes made within it."}

{"answer": "yes", "explanation": "Indexes help the database engine locate rows quickly for any DML statement (SELECT, UPDATE, DELETE) whose WHERE clause references an indexed column, avoiding a full table scan."}

{"answer": "yes", "explanation": "SAVEPOINT allows rolling back to a specific named point within a transaction without undoing the entire transaction."}

{"answer": "no", "explanation": "EXPLAIN ANALYZE actually executes the query to provide real timing and row-count statistics; plain EXPLAIN shows the plan without executing it."}

{"answer": "pgvector", "explanation": "pgvector is the PostgreSQL extension that adds vector types and indexes for embedding similarity search."}

{"answer": "yes", "explanation": "A partial index (a PostgreSQL feature) only stores index entries for rows that satisfy the WHERE condition, reducing index size and maintenance cost."}

{"answer": "no", "explanation": "PostgreSQL implements SERIALIZABLE using Serializable Snapshot Isolation (SSI), a multiversion concurrency control mechanism that detects conflicts after the fact, rather than by locking the rows a transaction reads."}

{"answer": "yes", "explanation": "HTTP 201 'Created' specifically indicates that the request succeeded and a new resource was created as a result."}

{"answer": 204, "explanation": "HTTP 204 No Content indicates a successful request where the server intentionally returns an empty response body, commonly used after DELETE operations."}

{"answer": "yes", "explanation": "RFC 7231 explicitly classifies DELETE as an idempotent method, meaning repeated DELETE requests on the same resource have the same effect as a single request."}

{"answer": "no", "explanation": "The Access-Control-Allow-Origin header is sent by the server (not the client) to indicate which origin is permitted to access the resource."}

{"answer": "yes", "explanation": "HTTP 429 Too Many Requests was defined in RFC 6585 specifically to indicate that a client has exceeded a rate limit."}

{"answer": "no", "explanation": "It's the opposite: 4xx codes indicate client errors (e.g., 404 Not Found) and 5xx codes indicate server errors (e.g., 500 Internal Server Error)."}

{"answer": "Content-Type", "explanation": "The Content-Type HTTP header specifies the MIME type (media type) of the request or response body."}

{"answer": "yes", "explanation": "RFC 5789 explicitly states that PATCH is not idempotent, whereas PUT (defined in RFC 7231) is idempotent by definition."}

{"answer": "no", "explanation": "Plain == is vulnerable to timing attacks; one should use hash_equals() or password_verify() for constant-time comparison."}

{"answer": "yes", "explanation": "A CSRF token is generated by the server, tied to the user's session, and validated server-side on state-changing requests (POST, PUT, DELETE) to ensure the request originated from the legitimate application."}

{"answer": "Content-Security-Policy", "explanation": "The Content-Security-Policy HTTP header is used to define and enforce CSP rules that help mitigate XSS and other code injection attacks."}

{"answer": "no", "explanation": "OAuth 2.0 is an authorization protocol, not an authentication protocol, and the access token grants resource access rather than identifying the user (the ID token in OpenID Connect does that)."}

{"answer": "no", "explanation": "XSS is primarily prevented by output encoding/escaping when data is rendered to the browser, not by input validation before storage; input validation alone is insufficient because 'valid' data can still contain script that executes in the output context."}

{"answer": "code", "explanation": "In the OAuth 2.0 authorization code flow, the 'code' parameter is appended to the redirect_uri and is then exchanged at the token endpoint for an access token."}

{"answer": "yes", "explanation": "A refresh token is intentionally long-lived and its purpose is to mint new access tokens without requiring the user to log in again."}

{"answer": "no", "explanation": "The salt does not need to be secret; it is typically stored alongside the hash (e.g., in the $algo$salt$hash format), and its purpose is to prevent rainbow-table attacks, not to act as a secret key."}

{"answer": "no", "explanation": "In PHPUnit, a class must extend PHPUnit\\Framework\\TestCase for its test methods to be discovered and executed."}

{"answer": "no", "explanation": "setUp() runs before each individual test method; setUpBeforeClass() is the static method that runs once before all tests."}

{"answer": "no", "explanation": "A data provider in PHPUnit allows a test to run with multiple sets of arguments, not just one; each set produces a separate test execution."}

{"answer": "expectException", "explanation": "PHPUnit's expectException() method declares an expectation that an exception of a given class is thrown during the test."}

{"answer": "no", "explanation": "It's the opposite: a stub returns pre-programmed data, while a mock verifies which methods were called with what arguments."}

{"answer": "yes", "explanation": "In PHPUnit 10+, the #[DataProvider] PHP attribute is the recommended approach, while the @dataProvider docblock annotation is deprecated."}

{"answer": "no", "explanation": "PHPUnit allows test dependencies via the @depends annotation or the depends() method, enabling one test to use the return value of another."}

{"answer": "--random-order", "explanation": "PHPUnit's --random-order command-line option shuffles the test execution order."}

{"answer": "3-3", "explanation": "intdiv(7,2) is 3 and intdiv(-7,2) is -3 (truncation toward zero), concatenated gives the string '3-3'."}

{"answer": -9, "explanation": "In PHP, the ** operator has higher precedence than the unary minus, so -3**2 is parsed as -(3**2) = -9."}

{"answer": "true", "explanation": "Both '1e1' and '10' are numeric strings, so PHP compares them numerically: 1e1 equals 10, making the comparison true."}

{"answer": "other", "explanation": "The string 'a' does not loosely equal 0, so the switch falls through to the default case which echoes 'other'."}

{"answer": "2c", "explanation": "strtr with an array performs a single-pass longest-match-first replacement: 'ab' (longer key) matches before 'a', so 'ab' becomes '2' and 'c' remains, giving '2c'."}

{"answer": "[hello]", "explanation": "substr('hello', -10) with a negative start beyond the string length clamps to 0, returning the full string 'hello'."}

{"answer": "k,n,m", "explanation": "The + operator merges arrays keeping left-hand values for duplicate keys, so keys are k, n, m."}

{"answer": "yxz", "explanation": "usort sorts by index 2 (values 2,1,2 → order becomes [y,1],[x,2],[z,2]), then array_column extracts index 1 giving ['y','x','z'], imploded to 'yxz'."}

{"answer": 4, "explanation": "The spread operator unpacks the array as named arguments (a: 5, b: 1), so $a=5 and $b=1, giving 5-1=4."}

{"answer": 3, "explanation": "The method g() is called and returns 3, which is stored in $f; setting $p to null afterward doesn't affect the already-captured value, so $f() still yields 3."}

{"answer": "B", "explanation": "static::class uses late static binding and resolves to the class on which the method was called, which is B."}

{"answer": 10, "explanation": "The setter multiplies the value by 2 (5*2=10), and reading the property returns the stored value 10."}

{"answer": "BA", "explanation": "TB::f insteadof TA makes f() return 'B', and TA::f as g aliases TA's f as g returning 'A', so the concatenation is 'BA'."}

{"answer": 0, "explanation": "Each class that uses a trait gets its own independent copy of static properties, so CX::$n = 1 does not affect CY::$n which remains 0."}

{"answer": 2, "explanation": "In PHP, a return statement in a finally block overrides any return from the try or catch blocks, so the function returns 2."}

{"answer": "second", "explanation": "Throwing a new exception in a finally block replaces the original exception, so the LogicException('second') propagates and is caught by the outer catch block."}

{"answer": "App\\Foo|Baz", "explanation": "Baz::class resolves to the imported alias App\\Foo, while \\Baz::class resolves to the global class Baz, concatenated with a pipe."}

{"answer": "noyes", "explanation": "class_exists('Foo') looks for the global class \\Foo (not found), while class_exists('Ns\\Foo') finds the class defined in the Ns namespace."}

{"answer": "1,2,99", "explanation": "The foreach loop with & creates a reference to the last element ($a[2]); assigning $v=99 modifies $a[2] in place, so the array becomes [1,2,99]."}

{"answer": 3, "explanation": "Static variables in a method are shared across all instances and inherited subclasses; after three calls to inc(), $n is incremented to 3."}

{"answer": 11, "explanation": "send(10) assigns $x=10 after the yield, then return $x+1 evaluates to 11, which getReturn() retrieves."}

{"answer": "1,2,ok", "explanation": "yield from inner() yields 1 and 2, captures the return value 'ok' in $r, which is then yielded, producing the array [1, 2, 'ok'] that implode joins into '1,2,ok'."}

{"answer": "noyes", "explanation": "password_needs_rehash returns false (no) when the cost matches (4 vs 4) and true (yes) when the cost differs (4 vs 5)."}

{"answer": "strict-in", "explanation": "E_ALL (32767) has bit 2048 (E_STRICT) set, so E_ALL & 2048 equals 2048, which is not === 0, making the ternary evaluate to 'strict-in'."}

{"answer": "mapped", "explanation": "Symfony's Request::create sets HTTP_X_TOKEN as a server variable, which is automatically converted to the header X-Token, so headers->get('X-Token') returns 'abc' and the strict comparison succeeds."}

{"answer": "BCA", "explanation": "Symfony EventDispatcher calls listeners in descending priority order: B (10), C (5), A (0)."}

{"answer": "same", "explanation": "Doctrine ORM's identity map guarantees that calling EntityManager::find() with the same ID within the same EM instance always returns the identical object reference, so $a and $b are the same instance."}

{"answer": 0, "explanation": "Persisting then removing an entity before flush cancels the insertion, so after flush the users table remains empty."}

{"answer": 1, "explanation": "COUNT(x) counts only non-NULL values in column x; there is one row with x=1 and one with x=NULL, so the result is 1."}

{"answer": "10,30,60", "explanation": "The window function sum(x) OVER (ORDER BY id) produces a running sum (10, 30, 60), and string_agg concatenates them as text with commas."}

{"answer": "M1M2", "explanation": "Each middleware echoes its tag before delegating to the next in the stack, so M1 echoes 'M1', then M2 echoes 'M2' before the (non-existent) handler is reached."}

{"answer": 1, "explanation": "When multiple handlers are registered for the same message class in Symfony Messenger, the HandleMessageMiddleware uses the first handler in the array (h1), which increments $n by 1."}

{"answer": 1, "explanation": "The first INSERT adds a row with value 1, the second INSERT is skipped due to the unique constraint combined with ON CONFLICT DO NOTHING, so the table contains exactly 1 row."}

{"answer": 2, "explanation": "The UNIQUE constraint is DEFERRABLE INITIALLY DEFERRED, so the uniqueness check is postponed until the end of the transaction, allowing both INSERTs to succeed and count(*) to return 2."}

{"answer": 6, "explanation": "The --filter test_sum regex matches both test_sum (3 data sets) and test_sum_abs (3 data sets), totaling 6 tests."}

{"answer": "2, 1", "explanation": "The data provider yields two cases ([1] and [-1]); test with x=1 passes assertTrue(1>0), test with x=-1 fails assertTrue(-1>0)."}

{"answer": "POST", "explanation": "The -d (--data) flag in curl causes the request to use the POST method by default."}

{"answer": "GET", "explanation": "The -G flag combined with -d causes curl to send the data as a URL query string, making it a GET request instead of the default POST."}

{"answer": "invalid_client", "explanation": "Per RFC 6749 §5.2, an unknown (non-existent) client_id causes the token endpoint to return the error value 'invalid_client'."}

{"answer": "fragment", "explanation": "In the OAuth 2.0 implicit flow (response_type=token), the access token is returned in the URI fragment (after #) of the redirect_uri, not in the query string."}

{"answer": 0, "explanation": "The default filter only triggers on null, not false, so false|default(2) yields false; false * 3 equals 0."}

{"answer": "a3", "explanation": "In Twig, the + operator has higher precedence than the ~ (concatenation) operator, so the expression is parsed as 'a' ~ (1 + 2), which equals 'a3'."}

{"answer": 0, "explanation": "Assert\\NotBlank() applied to an array checks if it is non-empty; [''] has one element so it passes, resulting in 0 violations."}

{"answer": "LogicException", "explanation": "Calling isValid() on a Symfony form that has not been submitted throws a LogicException, which is caught and its class name is printed."}

{"answer": "same", "explanation": "Symfony's DI container by default shares (singleton) services, so calling get() twice returns the same object instance."}

{"answer": "hi Bob!", "explanation": "Symfony's ContainerBuilder recursively resolves %param% references, so message '%greeting%!' → 'hi %name%!' → 'hi Bob!'."}

{"answer": "960px", "explanation": "In Bootstrap 5.3, at the lg breakpoint (min-width: 992px), the .container class has a max-width of 960px."}

{"answer": "text-danger", "explanation": "In Bootstrap 5.3's generated CSS, .text-danger appears later in the stylesheet than .text-primary, so with equal specificity it wins the cascade."}

{"answer": 2, "explanation": "Domain can only depend on Domain, but OrderService references both Application (PlaceOrder) and Infrastructure (Db), creating two violations."}

{"answer": 3, "explanation": "The class is in the Domain layer but depends on Application (PlaceOrder) and Infrastructure (Db, Logger), giving 3 violations since Domain may only depend on Domain."}

{"answer": "10,15", "explanation": "$a->amount is 10 and $c->amount is 10+5=15, concatenated with a comma gives '10,15'."}

{"answer": 1, "explanation": "The remove() method throws an exception when count is 1, so unset() is never called and the item 'a' remains in the array, making count() return 1."}

{"answer": "hi", "explanation": "The code instantiates class C and calls its hi() method which returns the string 'hi', then echoes it."}

{"answer": "yesno", "explanation": "The first isUninitializedLazyObject check returns true (object not yet initialized), printing 'yes'; after accessing $o->v the lazy object is initialized, so the second check returns false, printing 'no'."}

{"answer": "no", "explanation": "The entire Symfony Security Guard component (Symfony\\Component\\Security\\Guard) was removed in Symfony 7.0, so by Symfony 8.1 the AbstractGuardAuthenticator class no longer exists."}

{"answer": "noyes", "explanation": "In Symfony 8.1, AnnotationClassLoader has been removed (deprecated in 7.x), while AttributeClassLoader remains as its replacement."}