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

{"answer": "no", "explanation": "Double-quoted strings interpolate variables and interpret escape sequences (\\n, \\t, etc.), while single-quoted strings only recognize backslash-escaped single quotes and backslashes, so they are not processed identically."}

{"answer": "yes", "explanation": "The null coalescing operator (??) is syntactic sugar for isset($a) ? $a : $b, so it checks isset() semantics and does not raise warnings for undefined variables."}

{"answer": "ab", "explanation": "In PHP, echo accepts multiple comma-separated arguments and outputs them in sequence, so 'a' and 'b' are printed as 'ab'."}

{"answer": "yes", "explanation": "In PHP, print is a language construct that returns the integer 1, so it can be used in expressions (e.g., $x = print 'hello'; assigns 1 to $x)."}

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

{"answer": "no", "explanation": "In PHP, the concatenation operator (.) is at the same precedence level as addition (+) and subtraction (-), all in the 'additive' category, so it does not have lower precedence than them."}

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

{"answer": 3, "explanation": "Concatenation (.) has higher precedence than addition (+), so it parses as ('sum: ' . 2) + 3, which becomes 'sum: 2' + 3, and since 'sum: 2' casts to 0, the result is 3."}

{"answer": "no", "explanation": "With ===, arrays must have the same key/value pairs in the same order and of the same type; order matters with strict comparison."}

{"answer": "no", "explanation": "0 == false is a loose (not strict) comparison, and it actually returns true, not false."}

{"answer": "no", "explanation": "In PHP 8, when a non-numeric string like 'abc' is compared with an integer using ==, the integer is cast to a string, so 'abc' == '0' evaluates to false."}

{"answer": "yes", "explanation": "In PHP, under loose comparison (==), null is indeed equal to 0, the empty string '', and false, as all these values are considered 'falsy' and compare equal to null."}

{"answer": 42, "explanation": "Casting a string to int in PHP reads leading numeric characters until a non-numeric character is encountered, so '42abc' becomes 42."}

{"answer": 10, "explanation": "PHP coerces the numeric string '5' to an integer, so the expression evaluates to the integer 10."}

{"answer": "no", "explanation": "In PHP, casting false to a string results in an empty string \"\", not \"0\"; only the integer 0 casts to \"0\"."}

{"answer": "yes", "explanation": "Due to floating-point precision, 0.1 + 0.2 evaluates to 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 into invalid sequences rather than reversing whole characters."}

{"answer": "yes", "explanation": "str_contains checks if the needle 'world' is found within the haystack 'Hello world', which it is, so it returns true."}

{"answer": "no", "explanation": "str_pad() can pad on the right (STR_PAD_RIGHT), 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": "strlen counts bytes: 'h'(1) + 'é'(2 in UTF-8) + 'l'(1) + 'l'(1) + 'o'(1) = 6 bytes."}

{"answer": "def", "explanation": "substr with a negative start of -3 begins 3 characters from the end of 'abcdef', returning 'def'."}

{"answer": "no", "explanation": "ucfirst() returns a new string with the first character uppercased; it does not modify the original string in place since PHP strings are passed by value by default."}

{"answer": "yes", "explanation": "In PHP, heredoc (<<<EOF) supports variable interpolation while nowdoc (<<<'EOF') treats content like a single-quoted string, so no variables are interpolated."}

{"answer": "no", "explanation": "The sort() function re-indexes the array numerically starting from 0, discarding original keys; use asort() to preserve key-value associations."}

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

{"answer": "no", "explanation": "in_array() has a $strict parameter that defaults to false, meaning it uses loose comparison (==) by default."}

{"answer": "yes", "explanation": "Without a callback, array_filter() removes all elements that evaluate to false (0, '', null, false, '0', 0.0, empty array)."}

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

{"answer": "[20, 30]", "explanation": "array_slice extracts 2 elements starting at index 1 from the array, which are 20 and 30."}

{"answer": 2, "explanation": "The array union operator (+) keeps the left array's 'a' => 1 and only adds 'b' => 2 from the right array, since 'a' already exists in the left, resulting in 2 elements."}

{"answer": "yes", "explanation": "PHP 8.1 introduced array unpacking (spread operator) within array expressions, and unlike the earlier function-argument spread, it supports both integer and string keys."}

{"answer": "no", "explanation": "Named arguments can be combined with argument unpacking (...$args) in a single call, provided the named argument appears before the spread expression (e.g., foo(a: 1, ...$args) is valid in PHP 8+)."}

{"answer": "no", "explanation": "In PHP, anonymous functions (closures) do not automatically inherit variables from the enclosing scope; you must explicitly use the 'use' keyword to import them."}

{"answer": 3, "explanation": "func_num_args() returns the number of arguments actually passed to the function call, which is 3 (1, 2, 3), regardless of the declared parameter count."}

{"answer": "no", "explanation": "An arrow function (fn) in PHP has a single expression as its body (using =>), not multiple expressions in curly braces; curly braces are used for regular closures (function keyword)."}

{"answer": "no", "explanation": "PHP arrow functions (fn) automatically capture outer variables by value at creation time, not by reference at use time."}

{"answer": "yes", "explanation": "In PHP, declaring a closure as static prevents it from automatically capturing $this, unlike a non-static closure defined within a class context."}

{"answer": 5, "explanation": "The 'use' keyword captures the variable by value at the time the closure is defined, so the closure retains $x = 5 even after $x is reassigned to 7."}

{"answer": "yes", "explanation": "In coercive typing mode (without strict_types=1), PHP automatically coerces the numeric string \"5\" to the integer 5 when passed to an int parameter."}

{"answer": "yes", "explanation": "Constructor property promotion was introduced in PHP 8.0, allowing visibility modifiers and types to be declared directly on constructor parameters to automatically create and assign the property."}

{"answer": "final", "explanation": "In PHP, the 'final' keyword prevents a method from being overridden in subclasses."}

{"answer": "yes", "explanation": "In PHP, declaring a method as final prevents any subclass from overriding it; attempting to do so results in a fatal error."}

{"answer": "no", "explanation": "In PHP, private properties are only accessible within the class that declares them, not in subclasses; only public and protected properties are accessible in a subclass."}

{"answer": "class@anonymous", "explanation": "In PHP, anonymous classes created with `new class {}` receive a generated name prefixed with `class@anonymous`, which is the portion before the NUL byte/file path identifier."}

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

{"answer": "no", "explanation": "__get() is called when reading from an inaccessible (private or protected) property, not for non-existent properties."}

{"answer": "Error", "explanation": "Reassigning a readonly property in PHP throws a TypeError, which extends Error (not Exception)."}

{"answer": "yes", "explanation": "PHP interfaces can declare public constants, which are inherited by implementing classes."}

{"answer": "instanceof", "explanation": "In PHP, the instanceof operator is used to check whether an object is an instance of a specific class or implements a specific interface."}

{"answer": "yes", "explanation": "Since PHP 8.1, interfaces are allowed to declare static methods (which do not need to be implemented by the implementing class)."}

{"answer": "no", "explanation": "In PHP, the instanceof operator checks both class inheritance and interface implementation, so it does not ignore interfaces."}

{"answer": "no", "explanation": "In PHP, interface methods are always abstract (no body); only traits (and classes) can provide a default method implementation."}

{"answer": "yes", "explanation": "In PHP, abstract methods in an abstract class can be declared as public, protected, or private (since PHP 7.1)."}

{"answer": 3, "explanation": "The enum Foo declares three cases (A, B, C), so Foo::cases() returns an array of 3 elements."}

{"answer": "yes", "explanation": "Since PHP 8.2, traits are allowed to declare constants, which are then inherited by any class that uses the trait."}

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

{"answer": "no", "explanation": "TypeError extends Error, not Exception; they are siblings under the Throwable interface, so catch(Exception) does not catch TypeError."}

{"answer": "no", "explanation": "The @ operator only suppresses errors (warnings, notices, etc.) via error_reporting; exceptions are still thrown and propagated normally."}

{"answer": "DivisionByZeroError", "explanation": "In PHP 8.0+, intdiv(5, 0) throws a DivisionByZeroError, which extends ArithmeticError which extends Error."}

{"answer": "no", "explanation": "The finally block in PHP executes regardless of whether an exception was thrown, caught, or neither; it always runs after the try/catch blocks."}

{"answer": "no", "explanation": "An exception thrown in a finally block replaces (masks) any exception that was about to propagate from the try/catch block, so it does affect the final outcome."}

{"answer": "yes", "explanation": "In PHP, casting any object to bool always yields true."}

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

{"answer": "no", "explanation": "The 'use' statement only registers a namespace alias at compile time; the class file is actually loaded (via autoload) only when the class is first referenced (instantiated, static call, etc.)."}

{"answer": "function", "explanation": "In PHP, to import a function you use 'use function', while 'use const' is for importing constants."}

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

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

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

{"answer": "no", "explanation": "An unqualified class name in `new` is resolved relative to the current namespace, not the global root; only a name with a leading backslash (e.g., `\\Foo`) is resolved from the global namespace."}

{"answer": "yes", "explanation": "Under the PSR-4 mapping App\\ → src/, the remaining namespace Model\\User is converted to the relative path Model/User.php, giving src/Model/User.php."}

{"answer": "yes", "explanation": "PHP allows `use` statements inside a function (or any block), and the alias applies only within that scope."}

{"answer": "yes", "explanation": "In PHP, arrays use value semantics: assigning an array to a new variable creates a copy (with a Copy-on-Write optimization internally), not a reference."}

{"answer": 2, "explanation": "PHP arrays are assigned by value, so modifying $b after the assignment does not affect $a, which still has 2 elements."}

{"answer": "yes", "explanation": "In PHP, variables defined in the global scope are not accessible inside a function unless explicitly imported via global, $GLOBALS, or passed as parameters."}

{"answer": "no", "explanation": "unset($GLOBALS['x']) removes the variable from the global scope entirely, not just locally within that function; $GLOBALS directly references the global symbol table."}

{"answer": 6, "explanation": "The function increments $x by reference, so $n is modified from 5 to 6."}

{"answer": "no", "explanation": "A foreach by value iterates over a copy of the array, so modifications to the original array (adding/removing/changing elements) are not visible during the current pass."}

{"answer": "no", "explanation": "Static properties belong to the class itself, so all instances share the same copy and changes in one instance are visible in all others."}

{"answer": "no", "explanation": "In PHP, a boolean key `true` in an array is cast to the integer `1`, not stored as a bool."}

{"answer": "yes", "explanation": "In PHP generators, a return statement with a value is allowed, and that value can be retrieved after the generator is exhausted by calling $gen->getReturn()."}

{"answer": "no", "explanation": "Once a generator is fully consumed (closed), calling rewind() throws a LogicException; it can only be rewound if it has not yet been fully iterated."}

{"answer": "yes", "explanation": "The yield from construct (in Python) does delegate iteration to another iterable or generator, yielding each item in turn."}

{"answer": "Generator", "explanation": "Calling a generator function returns a Generator object, and get_class() on that object returns the string 'Generator'."}

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

{"answer": "no", "explanation": "SplStack implements a LIFO (Last In, First Out) stack, while SplQueue is the class that implements a FIFO queue."}

{"answer": "yes", "explanation": "ArrayIterator is an SPL class that wraps an array and implements the Iterator interface, allowing traversal via foreach or manual iterator methods."}

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

{"answer": "yes", "explanation": "PHP's password_hash() automatically generates and embeds a random salt in the resulting hash string, so no separate salt parameter is required."}

{"answer": "no", "explanation": "In PHP 8, PASSWORD_DEFAULT is bcrypt (not md5); md5 is a simple cryptographic hash and is not used by PHP's password hashing functions."}

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

{"answer": "no", "explanation": "strip_tags() only removes HTML/PHP tags from a string; SQL injection protection requires prepared statements or parameterized queries, not tag stripping."}

{"answer": "yes", "explanation": "session_regenerate_id() generates a new session ID, invalidating the old one, which prevents an attacker from hijacking a session with a known ID (session fixation)."}

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

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

{"answer": "no", "explanation": "In PHP, you must call session_start() before $_SESSION is populated with session data; without it, the array is either unavailable or empty."}

{"answer": "8.4", "explanation": "array_find() is not a standard built-in PHP function; it was not officially introduced in any stable PHP version as of 8.4, making this likely a trick question, but 8.4 is the most recent version where new array helpers have been proposed."}

{"answer": "yes", "explanation": "Property hooks (inline get/set accessors in property declarations) were introduced in PHP 8.4."}

{"answer": "no", "explanation": "PHP 8.4 introduced property hooks (e.g., get/set on properties), but the specific asymmetric visibility syntax 'public private(set) string $name' was a separate proposal and is not the syntax adopted in PHP 8.4."}

{"answer": 8.4, "explanation": "The #[\\NoDiscard] attribute was introduced in PHP 8.4 to indicate that a function's return value should not be discarded."}

{"answer": "no", "explanation": "PHP does not have a pipe operator |>; the | symbol in PHP is the bitwise OR operator, and there is no dedicated |> pipe operator in any PHP version."}

{"answer": "8.4", "explanation": "The 'clone with' syntax, allowing property overrides during cloning (e.g., clone($obj, ['x' => 1])), was introduced in PHP 8.4."}

{"answer": "never", "explanation": "array_first() and array_last() are not built-in PHP functions in any released version of PHP; they are typically custom helpers or part of frameworks like Laravel."}

{"answer": "8.5", "explanation": "The RFC Partial Function Application v2 was adopted for PHP 8.5."}

{"answer": 9, "explanation": "The RFC clamp_v2 introducing the clamp() function was accepted for PHP 9.0."}

{"answer": "no", "explanation": "As of November 2026, no RFC specifically named 'Context Managers v2' has been formally adopted into PHP; while context-like features (e.g., the with-expression in 8.4) exist, a dedicated 'Context Managers v2' RFC is not part of the adopted feature set."}

{"answer": "yes", "explanation": "The RFC for Bound-Erased Generic Types (generics) in PHP was voted down/declined in 2026."}

{"answer": "no", "explanation": "As of 2026, PHP has not accepted an RFC making ZTS (Zend Thread Safety) the default build; NTS remains the standard distribution."}

{"answer": "yes", "explanation": "PHP 8.5 does not include native generics or parameterized types; they remain absent from the language as of that version."}

{"answer": "yes", "explanation": "PHP follows a yearly November release cycle, so PHP 8.5 (GA Nov 2025) is the latest stable version before PHP 8.6's scheduled GA on 2026-11-19."}

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

{"answer": "no", "explanation": "The RFC proposing a built-in #[\\Deprecated] attribute was discussed but not accepted into the PHP core."}

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

{"answer": "yes", "explanation": "In Domain-Driven Design, domain entities are pure PHP classes that depend only on the language itself and possibly the standard library, keeping them free of framework-specific dependencies like Doctrine or Symfony."}

{"answer": "no", "explanation": "Controllers and Twig templates belong to the presentation (view) layer; they call use cases (application layer) but are not themselves part of the business-logic layer."}

{"answer": "Domain", "explanation": "In the onion architecture, the core domain model (entities and value objects) sits at the very center, surrounded by successive layers of services and adapters."}

{"answer": "yes", "explanation": "Tools like deptrac define allowed layer dependencies and automatically fail the build when a forbidden cross-layer call is detected."}

{"answer": "no", "explanation": "In Clean/Hexagonal Architecture a use case should be framework-agnostic: it receives plain data (or value objects) and depends on abstractions (e.g., a Repository interface), not on concrete types like an HTTP Request or a Doctrine EntityManager."}

{"answer": "Repository", "explanation": "A Repository provides a collection-like interface for accessing domain aggregates/entities while abstracting the underlying storage mechanism."}

{"answer": "yes", "explanation": "In clean architecture, the database is an infrastructure concern; the domain and use cases depend only on abstractions (interfaces), so swapping the database only affects the outer infrastructure layer."}

{"answer": "no", "explanation": "In DDD, an aggregate is a cluster of domain objects (entities and value objects) treated as a consistency boundary, not a synonym for a database table; the mapping between them is an implementation detail."}

{"answer": "yes", "explanation": "In DDD, a Value Object is defined as immutable and uses value-based equality (field comparison) rather than reference-based identity."}

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

{"answer": "yes", "explanation": "In DDD, a repository is defined for an Aggregate Root, treating the entire aggregate as a single consistency boundary, rather than creating separate repositories for each entity within the aggregate."}

{"answer": "yes", "explanation": "Ubiquitous Language, a key DDD concept, is precisely the shared language between developers and domain experts used consistently in the model, code, and discussions."}

{"answer": "frame", "explanation": "A frame is the boundary within which a model and its language remain self-consistent, while outside it the same terms may refer to different models."}

{"answer": "no", "explanation": "DDD recommends a rich domain model where business logic and behavior are encapsulated within domain objects, not delegated to external service classes."}

{"answer": "yes", "explanation": "In DDD, a Bounded Context ensures each context has its own model, so the same real-world concept is represented by different classes (with different attributes and behaviors) in different contexts."}

{"answer": "yes", "explanation": "Symfony's DI container instantiates services lazily by default, meaning a service object is only created the first time it is actually requested or injected."}

{"answer": "debug:router", "explanation": "The Symfony console command 'php bin/console debug:router' lists all registered routes with their methods, paths, and controllers."}

{"answer": "no", "explanation": "Autowiring automatically resolves dependencies via type hints, so services do not need to be manually declared in services.yaml."}

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

{"answer": "yes", "explanation": "In Symfony dev, the compiled container is cached in var/cache/dev/ and is only recompiled when tracked files (e.g., service configs) have a newer timestamp than the cache; otherwise the cached container is reused on each request."}

{"answer": "APP_ENV", "explanation": "The APP_ENV environment variable is used by Symfony to select the active environment (dev, prod, test)."}

{"answer": "no", "explanation": "In Symfony, the controller action method that a route points to must be public; private or protected methods cannot be called directly by the router/reflector."}

{"answer": "no", "explanation": "In PHP event systems (e.g., Symfony), subscribers and listeners share the same dispatch queue; order is determined by priority and registration order, not by the subscriber interface itself."}

{"answer": "yes", "explanation": "Symfony 6.0 removed the legacy guard authentication system; the modern approach uses custom authenticator classes implementing AuthenticatorInterface with Passport/Badge objects."}

{"answer": "IsGranted", "explanation": "The #[IsGranted] attribute in Symfony Security checks whether the current user has a specified role or permission on a controller method, and throws an AccessDeniedException (403) if not."}

{"answer": "yes", "explanation": "Symfony Voters are the built-in mechanism for object-level access control, used via isGranted('EDIT', $post) to check permissions against a specific object."}

{"answer": "yes", "explanation": "In Symfony 7 the Doctrine Annotations driver was removed, so validation constraints in code must be declared using PHP 8 attributes like #[Assert\\NotBlank]; (XML/YAML mappings remain as alternatives, but the Doctrine Annotations format is gone)."}

{"answer": "yes", "explanation": "Symfony forms include a CSRF token field and validate it on submission by default; it can only be disabled by explicitly setting 'csrf_protection' => false."}

{"answer": "yes", "explanation": "Symfony's form validation (via constraints like NotBlank, Length, etc.) is always executed server-side upon submission, regardless of whether client-side HTML5 validation already passed; the server is the authoritative validator."}

{"answer": "make:form", "explanation": "The Symfony MakerBundle command 'make:form' generates a FormType class for building forms."}

{"answer": "no", "explanation": "Symfony stores the user's identity (e.g., user ID and a token) in the session, not the password; the password is only hashed and kept in the database for comparison during authentication."}

{"answer": "yes", "explanation": "Symfony's recommended structure (especially with Symfony Flex) places each bundle's configuration in a separate YAML/XML/PHP file under config/packages/ (e.g., config/packages/doctrine.yaml)."}

{"answer": "yes", "explanation": "This is a standard convention: .env holds safe dev defaults committed to VCS, while .env.local holds real secrets and is gitignored."}

{"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 exposes setParameter() which can be called at runtime from a controller, though it won't affect services whose parameters were already inlined during compilation."}

{"answer": "no", "explanation": "Since Symfony 4, services are private (public: false) by default, allowing the container to optimize by dropping unused services."}

{"answer": "no", "explanation": "Many Symfony bundles work perfectly fine without a config file in config/packages, as they provide sensible defaults built into the bundle itself."}

{"answer": "yes", "explanation": "In Symfony, the %env(VAR)% syntax is used in configuration files like services.yaml to reference environment variable values."}

{"answer": "APP_DEBUG", "explanation": "In Symfony, the APP_DEBUG environment variable (set to true/false in the .env file) enables or disables debug mode, which controls the profiler, Twig debug tools, and other development features."}

{"answer": "no", "explanation": "Symfony Messenger supports assigning multiple handlers to a single message, which are executed in the order they are defined."}

{"answer": "no", "explanation": "The sync transport dispatches and handles the message immediately in the current process, without queueing it for a separate worker."}

{"answer": "messenger:consume", "explanation": "In Symfony, the command 'php bin/console messenger:consume' starts the worker that processes Messenger queue messages."}

{"answer": "no", "explanation": "Retry strategies in Symfony Messenger are configured globally, per bus, or per message (via RetryStrategyInterface), not per transport."}

{"answer": "yes", "explanation": "Symfony Messenger uses JSON as the default serialization format for messages when using transports."}

{"answer": "yes", "explanation": "Symfony Scheduler is designed to trigger scheduled tasks by dispatching messages through the Symfony Messenger component on defined schedules (e.g., cron expressions)."}

{"answer": "doctrine", "explanation": "Symfony Messenger's built-in 'doctrine' transport uses Doctrine DBAL to store and retrieve messages in database tables."}

{"answer": "yes", "explanation": "Symfony Messenger's pipeline is designed to be extensible, allowing developers to insert custom middleware before, after, or between the built-in middleware handlers."}

{"answer": "yes", "explanation": "Symfony major versions are released approximately every two years, and minor versions are released every six months in 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; annotations were deprecated in 6.4 and then removed in 7.0."}

{"answer": "yes", "explanation": "Symfony's AssetMapper component (introduced in 7.1) manages CSS and JS assets without requiring Node.js or Webpack, using an importmap.php (or importmap.json) file to define and track dependencies."}

{"answer": "no", "explanation": "Symfony 6.4 is actually a Long-Term Support (LTS) release, not a regular short-support release."}

{"answer": "yes", "explanation": "Symfony's deprecation policy keeps deprecated features working for at least one subsequent major version; a feature deprecated in 5.x is removed in 7.x, not 6.x."}

{"answer": "yes", "explanation": "Symfony consistently provides UPGRADE-*.md files in its repository documenting breaking changes and deprecations for each major release."}

{"answer": "AssetMapper", "explanation": "Symfony's AssetMapper component (introduced in Symfony 7.1) manages assets and import maps without requiring Node.js or webpack."}

{"answer": "no", "explanation": "Symfony minor releases in the November cycle are typically made at the end of November (around the 28th-29th), so as of November 7, 2026, Symfony 8.2 would not yet have been released."}

{"answer": "yes", "explanation": "Symfony follows a six-month release cycle, so 8.0 (Nov 2025), 8.1 (May 2026), and 8.2 (Nov 2026) align with that schedule."}

{"answer": "8.2", "explanation": "Following standard semver and Symfony's release cycle, the version immediately after 8.1 is 8.2."}

{"answer": "no", "explanation": "Symfony 8.2 (the '.2' part) is a minor/patch release within the 8.x major line, and even major Symfony releases involve removing deprecated features rather than requiring a full rewrite of applications."}

{"answer": "yes", "explanation": "PHP's backward-compatibility policy guarantees that no breaking changes are introduced within a major version (e.g., 8.x), so moving from 8.1 to 8.2 should not require code changes."}

{"answer": 8.4, "explanation": "Symfony 8.4 is the last minor (LTS) release in the 8.x branch before Symfony 9.0, following the pattern where .4 releases are the long-term support versions."}

{"answer": "no", "explanation": "Symfony 8.2 is not yet an established release with a confirmed PHP 8.5 requirement; the actual minimum PHP version for that future release is not definitively set to 8.5."}

{"answer": "yes", "explanation": "Symfony's deprecation policy guarantees that deprecations introduced in a major branch (e.g., 8.x) will only be removed in the next major version (9.0), preserving backward compatibility within the same major release."}

{"answer": "no", "explanation": "Inside {{ }}, Twig uses its own expression language (variables, filters, operators, method calls) rather than allowing arbitrary raw PHP code to be written directly."}

{"answer": "yes", "explanation": "Twig auto-escapes all output by default (using the 'html' escaping strategy) to protect against XSS attacks."}

{"answer": "yes", "explanation": "The Twig |e (escape) filter defaults to escaping a string 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 given locale."}

{"answer": "yes", "explanation": "The |raw filter (as in Twig) marks a value as already safe, telling the templating engine to skip auto-escaping."}

{"answer": "yes", "explanation": "In Twig, {{ }} is the variable/output tag that prints an expression's value, while {% %} is the statement tag used for control structures like if, for, and set."}

{"answer": "no", "explanation": "Twig allows you to declare variables inside a template using the 'set' tag, e.g. {% set foo = 'bar' %}."}

{"answer": "dump", "explanation": "Twig's built-in `dump()` function outputs a debug structure of a variable (array, object, etc.)."}

{"answer": "yes", "explanation": "Bootstrap is a front-end CSS/JS library providing ready-made UI components (buttons, modals, navbars, etc.), not an SPA framework like React, Angular, or Vue."}

{"answer": "container", "explanation": "The .container class in Bootstrap provides a responsive centered container with a fixed max-width that changes at each breakpoint, unlike .container-fluid which is always 100% width."}

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

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

{"answer": "yes", "explanation": "Spacing utilities like .mt-3 or .px-2 multiply the base spacing variable ($spacer) by the number in the class name."}

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

{"answer": "yes", "explanation": "Bootstrap 5 removed the jQuery dependency entirely; all its interactive components are implemented in plain vanilla JavaScript."}

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

{"answer": "no", "explanation": "Doctrine ORM does not auto-create tables at runtime; you must explicitly generate the schema via schema-tool commands or migrations."}

{"answer": "persist", "explanation": "EntityManager::persist() marks a new entity as managed without executing SQL until flush() is called."}

{"answer": "no", "explanation": "In Doctrine ORM 3, EntityManager::merge() was removed and replaced by EntityManager::toManaged()."}

{"answer": "yes", "explanation": "DQL (Doctrine Query Language) operates at the object level, using entity class names and their mapped fields rather than raw database table and column names."}

{"answer": "null", "explanation": "In PHP (e.g., Doctrine/Symfony repositories), the find() method 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; you must explicitly call $entityManager->flush() yourself (e.g., in a controller or service)."}

{"answer": "yes", "explanation": "For managed entities, the Unit of Work tracks property changes via its identity map, and flush() commits them without needing an explicit persist() call."}

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

{"answer": "no", "explanation": "MVCC in PostgreSQL specifically allows readers and writers to proceed concurrently without blocking each other, which is the opposite of what the statement claims."}

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

{"answer": "no", "explanation": "While both use sequences under the hood, SERIAL is a pseudo-type that creates a separate sequence object and sets a default, whereas GENERATED AS IDENTITY is a standard column property with BY DEFAULT/ALWAYS semantics, different catalog storage, and different lifecycle management."}

{"answer": "no", "explanation": "In PostgreSQL, NULL values are considered distinct from each other, so a UNIQUE constraint allows multiple rows with NULL by default (you need UNIQUE NULLS NOT DISTINCT, added in PG 15, to restrict it to one)."}

{"answer": "string_agg", "explanation": "string_agg(expression, delimiter) is the PostgreSQL aggregate function that concatenates strings with a specified separator."}

{"answer": "no", "explanation": "Plain VACUUM marks the space of dead tuples as reusable within the table but does not return it to the operating system; only VACUUM FULL rewrites the table and shrinks the file."}

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

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

{"answer": "yes", "explanation": "By default, PostgreSQL operates in autocommit mode, where each individual SQL statement is wrapped in its own implicit transaction and automatically committed upon completion."}

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

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

{"answer": "yes", "explanation": "SAVEPOINT in PostgreSQL allows you to roll back to a specific point within a transaction, effectively undoing only the statements executed after that savepoint."}

{"answer": "no", "explanation": "EXPLAIN ANALYZE actually executes the query and reports real timing and row counts, whereas plain EXPLAIN shows the plan without executing."}

{"answer": "pgvector", "explanation": "pgvector is the PostgreSQL extension that adds vector data types and approximate nearest-neighbor indexes (IVFFlat, HNSW) for embedding similarity search."}

{"answer": "yes", "explanation": "A partial index (e.g., in PostgreSQL) only stores index entries for rows that satisfy the WHERE condition, leaving the rest unindexed."}

{"answer": "no", "explanation": "PostgreSQL implements SERIALIZABLE using Serializable Snapshot Isolation (SSI), which detects conflicts after the fact rather than preemptively locking all rows a transaction reads."}

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

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

{"answer": "yes", "explanation": "Per RFC 2616 and RFC 9110, DELETE is listed as an idempotent method: repeating the request does not change the resource state (a second DELETE on an already-deleted resource is a no-op, yielding the same end state)."}

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

{"answer": "yes", "explanation": "HTTP 429 Too Many Requests is specifically defined for rate limiting, indicating the client has sent too many requests in a given time frame."}

{"answer": "no", "explanation": "It's the opposite: 4xx codes indicate client errors (e.g., 404, 400), while 5xx codes indicate server errors (e.g., 500, 503)."}

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

{"answer": "yes", "explanation": "RFC 5789 explicitly states that PATCH is not idempotent, while PUT (defined in RFC 7231) is required to be idempotent."}

{"answer": "no", "explanation": "A plain '==' comparison is vulnerable to timing attacks and loose type juggling; you should use hash_equals() for a constant-time, strict comparison of password hashes."}

{"answer": "yes", "explanation": "CSRF tokens are generated server-side, tied to the user's session, and validated on the server for state-changing requests like POST, PUT, or DELETE to ensure the request originated from the legitimate application."}

{"answer": "Content-Security-Policy", "explanation": "The Content-Security-Policy HTTP header is used to declare and enforce a Content Security Policy for a web resource."}

{"answer": "no", "explanation": "OAuth 2.0 is an authorization protocol, not an authentication protocol; it grants access to resources via tokens rather than identifying who the user is (that is the role of OpenID Connect built on top of OAuth 2.0)."}

{"answer": "no", "explanation": "XSS is primarily prevented by encoding/escaping output when it is rendered in the browser, not by validating input before storing it in the database."}

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

{"answer": "yes", "explanation": "Refresh tokens are indeed longer-lived than access tokens and are specifically designed to obtain new access tokens without requiring the user to log in again."}

{"answer": "no", "explanation": "A salt does not need to be secret; it is typically stored alongside the hash so that verification can re-derive the expected hash from the candidate password."}

{"answer": "no", "explanation": "PHPUnit requires test classes to extend PHPUnit\\Framework\\TestCase in order to be recognized and executed by the test runner."}

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

{"answer": "no", "explanation": "A data provider's purpose is to supply multiple sets of arguments so the test runs once per data set, not just once."}

{"answer": "expectException", "explanation": "PHPUnit's expectException() method declares that an exception of the specified class is expected to be thrown."}

{"answer": "no", "explanation": "It's the opposite: a stub only returns predefined data, while a mock both returns data and verifies expectations about method calls."}

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

{"answer": "no", "explanation": "PHPUnit supports test dependencies via the @depends annotation or the depends() method, allowing one test to receive the return value of another as a parameter."}

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

{"answer": "3-3", "explanation": "intdiv(7,2) truncates 3.5 to 3, intdiv(-7,2) truncates -3.5 toward zero to -3, and the dot operator concatenates them into 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 expression true."}

{"answer": "other", "explanation": "In PHP 8, the string 'a' is not equal to 0 under loose comparison (==), so the switch falls through to the default case and outputs 'other'."}

{"answer": "2c", "explanation": "strtr with an array replaces the longest matching key first, so 'ab' (length 2) is matched before 'a' (length 1), turning 'abc' into '2c'."}

{"answer": "[]", "explanation": "substr('hello', -10) returns an empty string because the negative start position (-10) goes beyond the 5-character string, so the result is '[]'."}

{"answer": "k,n,m", "explanation": "The + operator performs array union, keeping left-side values for duplicate keys, so the result is ['k'=>1,'n'=>2,'m'=>3'], and array_keys gives ['k','n','m']. "}

{"answer": "yxz", "explanation": "usort sorts by the 3rd element (index 2) ascending, yielding [2,'y',1], [1,'x',2], [3,'z',2]; array_column then extracts index 1 giving ['y','x','z'], and implode concatenates to 'yxz'."}

{"answer": 4, "explanation": "The spread operator with string keys maps 'a' => 5 and 'b' => 1 by name, so f(5, 1) returns 5 - 1 = 4."}

{"answer": 3, "explanation": "The first-class callable syntax $p->g(...) captures the object handle into the closure, so setting $p = null doesn't affect the closure's internal reference; calling $f() still invokes g() on the P object and returns 3."}

{"answer": "B", "explanation": "static::class uses late static binding, so it resolves to the class of the actual object instance, which is B."}

{"answer": 10, "explanation": "The set hook multiplies the assigned value by 2 (5*2=10), and assigning $this->x inside the set hook stores directly without re-triggering the hook."}

{"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 output is 'BA'."}

{"answer": 0, "explanation": "Each class that uses a trait gets its own independent copy of static properties, so CY::$n remains 0 while CX::$n is set to 1."}

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

{"answer": "second", "explanation": "The finally block throws a LogicException('second'), which replaces the original RuntimeException, and the outer catch catches the LogicException and prints its message."}

{"answer": "App\\Foo|Baz", "explanation": "Baz::class resolves to App\\Foo via the use alias, while \\Baz::class refers to the global Baz class, yielding 'App\\Foo|Baz'."}

{"answer": "noyes", "explanation": "class_exists('Foo') looks for a global class Foo (not found, gives 'no'), while class_exists('Ns\\Foo') finds the namespaced class (gives 'yes'), concatenating to 'noyes'."}

{"answer": "1,2,99", "explanation": "After a foreach by reference, $v remains a reference to the last element of $a, so assigning 99 to $v modifies $a[2]."}

{"answer": 3, "explanation": "The local static variable $n is shared between A and B since B inherits the method; successive calls increment it to 1, 2, 3, and the third call outputs 3."}

{"answer": 11, "explanation": "The generator yields 1, receives 10 via send(), assigns it to $x, then returns $x + 1 = 11, which is retrieved by getReturn()."}

{"answer": "1,2,ok", "explanation": "yield from inner() delegates yielding 1 and 2 to the caller, assigns the return value 'ok' to $r, then outer yields 'ok', producing the sequence 1, 2, 'ok' which implode joins as '1,2,ok'."}

{"answer": "noyes", "explanation": "password_needs_rehash returns false when cost matches (4==4, prints 'no') and true when cost differs (4!=5, prints 'yes'), so the concatenated output is 'noyes'."}

{"answer": "strict-in", "explanation": "E_ALL includes E_STRICT (2048), so (E_ALL & 2048) equals 2048, which is not === 0, so the ternary returns 'strict-in'."}

{"answer": "mapped", "explanation": "Symfony converts the HTTP_X_TOKEN server variable into the header 'X-Token', so headers->get('X-Token') returns 'abc'."}

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

{"answer": "same", "explanation": "Doctrine ORM's find() checks the first-level identity map before querying the database; since the entity is already managed, both calls return the exact same object instance."}

{"answer": 0, "explanation": "After persist() the entity is in the 'new' (toInsert) set; remove() moves it to the scheduled-for-deletion set and out of toInsert, so flush() never issues an INSERT, leaving the empty table with 0 rows."}

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

{"answer": "10,30,60", "explanation": "The window function sum(x) OVER (ORDER BY id) produces running totals 10, 30, 60, which string_agg concatenates with commas in id order."}

{"answer": "M1M2", "explanation": "The two Trace middleware execute in order, each echoing its tag before delegating to the next, producing 'M1' then 'M2' concatenated."}

{"answer": 11, "explanation": "HandleMessageMiddleware iterates over all handlers returned by HandlersLocator for the message class, so both closures execute: $n += 1 then $n += 10, resulting in 11."}

{"answer": 1, "explanation": "The first INSERT succeeds, the second hits the unique index conflict and is skipped due to ON CONFLICT DO NOTHING, leaving exactly 1 row."}

{"answer": 2, "explanation": "The UNIQUE constraint is DEFERRABLE INITIALLY DEFERRED, so both inserts succeed within the transaction and the count returns 2 before any commit-time check."}

{"answer": 6, "explanation": "--filter test_sum matches both test_sum (3 data sets) and test_sum_abs (3 data sets) as the filter is a substring/regex match, totaling 6 tests."}

{"answer": "2, 1", "explanation": "The data provider yields two datasets ([1] and [-1]); assertTrue(1>0) passes but assertTrue(-1>0) fails, so 2 ran, 1 failed."}

{"answer": "POST", "explanation": "The -d flag in curl sends data in the request body and implicitly sets the HTTP method to POST when no explicit method is specified."}

{"answer": "GET", "explanation": "The -G flag forces curl to use the GET method and append the -d data as a query string to the URL."}

{"answer": "unauthorized_client", "explanation": "Per RFC 6749 §5.2, a non-existent (unrecognized) client_id at the token endpoint results in the 'unauthorized_client' error."}

{"answer": "fragment", "explanation": "In the OAuth 2.0 implicit flow (response_type=token), the access token is returned in the URI fragment (after #), not in the query string, so it is not transmitted to the server in subsequent requests."}

{"answer": 0, "explanation": "The default filter only replaces null values, not false, so false * 3 evaluates to 0."}

{"answer": 2, "explanation": "In Twig, ~ has higher precedence than +, so the expression is parsed as ('a' ~ 1) + 2, which evaluates to 'a1' + 2 = 2 via PHP's string-to-int coercion."}

{"answer": 0, "explanation": "The array [''] has a count of 1, so the NotBlank constraint (which checks if array count is 0) does not trigger a violation, resulting in 0 violations."}

{"answer": "Symfony\\Component\\Form\\Exception\\LogicException", "explanation": "Calling isValid() on a Symfony form that has never been submitted throws a LogicException, which is caught and its class name is printed."}

{"answer": "same", "explanation": "Symfony DI container services are singletons by default, so get('a') returns the same cached stdClass instance both times."}

{"answer": "hi Bob!", "explanation": "The parameter 'message' is '%greeting!%' which resolves '%greeting%' to 'hi %name%', then '%name%' resolves to 'Bob', yielding 'hi Bob!'."}

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

{"answer": "text-danger", "explanation": "In Bootstrap 5.3's generated CSS, .text-danger appears after .text-primary with equal specificity, so the later rule (.text-danger) wins the cascade."}

{"answer": 2, "explanation": "The Domain layer may only depend on Domain; here it depends on both Application (PlaceOrder) and Infrastructure (Db), giving 2 violations."}

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

{"answer": "10,15", "explanation": "$a remains unchanged with amount 10 (readonly), and $c is a new Money object with amount 10+5=15."}

{"answer": 1, "explanation": "The remove() method throws a DomainException when count is 1, so unset() is never reached and the item remains, making the final count 1."}

{"answer": "hi", "explanation": "The code creates an instance of class C, calls the hi() method which returns the string 'hi', and echoes it."}

{"answer": "yesno", "explanation": "After newLazyGhost the object is uninitialized (prints 'yes'); accessing $o->v triggers the init callback, making it initialized (prints 'no')."}

{"answer": "no", "explanation": "The Guard authentication component (including AbstractGuardAuthenticator) was removed in Symfony 7.0, so it no longer exists in Symfony 8.1."}

{"answer": "noyes", "explanation": "In Symfony 8.1, AnnotationClassLoader was removed (deprecated in 6.4, removed in 7.0), while AttributeClassLoader is the current standard class, so class_exists returns false then true, printing 'no' and 'yes'."}