Карта знаний PHP — deepseek-flash, run-10 · think: low

{"answer":"no","explanation":"Double-quoted strings interpolate variables and interpret escape sequences, while single-quoted strings do not, so they are not processed identically."}

{"answer":"yes","explanation":"The null coalescing operator (??) uses isset semantics, so undefined variables do not trigger warnings."}

{"answer":"ab","explanation":"echo outputs each argument in order, so 'a' followed by 'b' prints ab."}

{"answer":"yes","explanation":"In PHP, print returns 1 and can be used within expressions."}

{"answer":"no","explanation":"The elvis operator returns its left operand when it is truthy, not falsy."}

{"answer":"yes","explanation":"PHP 8 lowered the precedence of the concatenation operator (.) below addition and subtraction."}

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

{"answer":"sum: 5","explanation":"In PHP 8, addition has higher precedence than concatenation, so it evaluates as 'sum: ' . (2 + 3)."}

{"answer":"no","explanation":"With ===, arrays must have the same key/value pairs in the same order and of the same types to be equal."}

{"answer":"no","explanation":"In PHP, 0 == false evaluates to true because == is a loose comparison, not strict."}

{"answer":"no","explanation":"In PHP 8, comparing a non-numeric string to 0 no longer treats the string as 0, so \"abc\" == 0 is false."}

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

{"answer": 42, "explanation": "PHP casts the leading numeric part of the string, so '42abc' becomes the integer 42."}

{"answer": 10, "explanation": "PHP converts the numeric string '5' to an integer and adds it to 5, yielding 10."}

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

{"answer": "yes", "explanation": "0.1 + 0.2 is not exactly equal to 0.3 in binary floating-point, so strict comparison returns false."}

{"answer":"no","explanation":"strrev() reverses bytes, not UTF-8 characters, so it can corrupt multibyte strings."}

{"answer":"yes","explanation":"PHP's str_contains returns true when the substring 'world' is found in 'Hello world'."}

{"answer": "no", "explanation": "str_pad() can pad on the left, right, or both sides depending on the pad_type argument."}

{"answer":"no","explanation":"By default trim() strips spaces, tabs, newlines, carriage returns, NUL bytes, and vertical tabs."}

{"answer": 6, "explanation": "strlen() counts bytes, and the UTF-8 é occupies 2 bytes, giving 1+2+1+1+1 = 6."}

{"answer":"def","explanation":"A negative start offsets from the end of the string, returning the last three characters."}

{"answer":"no","explanation":"ucfirst() returns a new string and does not modify the original argument in place."}

{"answer": "yes", "explanation": "Heredoc interpolates variables, while nowdoc treats content literally without interpolation."}

{"answer": "no", "explanation": "sort() reindexes the array's numeric keys, so it does not preserve key-to-value associations."}

{"answer":"yes","explanation":"PHP converts numeric string array keys like '5' to the integer 5."}

{"answer":"no","explanation":"By default in_array() uses loose comparison; strict comparison requires the third parameter set to true."}

{"answer":"yes","explanation":"array_filter() with no callback keeps only elements that evaluate to true, removing falsy values."}

{"answer":"no","explanation":"By default array_slice() reindexes numeric keys; set preserve_keys to true to keep them."}

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

{"answer": 2, "explanation": "The array union operator keeps the left value for duplicate keys, so the result has keys 'a' and 'b'."}

{"answer":"yes","explanation":"PHP 8.1 added support for string keys in array unpacking with the spread operator."}

{"answer":"no","explanation":"PHP allows argument unpacking before named arguments; only unpacking after named arguments is disallowed."}

{"answer": "no", "explanation": "PHP closures do not automatically capture outer-scope variables; they must be imported with use."}

{"answer": 3, "explanation": "func_num_args() returns the total number of arguments passed to the function, including extra arguments beyond declared parameters."}

{"answer":"no","explanation":"PHP arrow functions have a single expression body and do not support a curly-braced block with multiple expressions."}

{"answer":"no","explanation":"PHP arrow functions capture outer variables by value automatically, not by reference."}

{"answer": "yes", "explanation": "Static anonymous functions are not bound to $this, so they cannot capture or use it."}

{"answer":5,"explanation":"The closure captures $x by value when defined, so it returns the original value 5."}

{"answer": "yes", "explanation": "In weak typing mode, PHP coerces numeric strings like \"5\" to int for int parameters."}

{"answer": "yes", "explanation": "PHP 8.0 introduced constructor property promotion, allowing parameters like private int $x to declare and initialize properties."}

{"answer":"final","explanation":"The final keyword prevents a method from being overridden in subclasses."}

{"answer":"yes","explanation":"In PHP, a method declared final cannot be overridden by a subclass."}

{"answer":"no","explanation":"Private properties are accessible only within the class that declares them, not in subclasses."}

{"answer":"class@anonymous","explanation":"get_class() on an anonymous class returns a name starting with \"class@anonymous\" followed by a NUL byte and file/line info."}

{"answer": "yes", "explanation": "Private parent methods are not inherited as part of the child’s contract, so a child can redeclare the same name with any visibility."}

{"answer": "no", "explanation": "__get() is also called when accessing inaccessible (private/protected) properties, not only non-existent ones."}

{"answer":"Error","explanation":"Reassigning a readonly property throws an Error, not an Exception."}

{"answer":"yes","explanation":"PHP interfaces can declare constants, which implementing classes inherit and cannot override."}

{"answer":"instanceof","explanation":"The instanceof operator determines whether an object is an instance of a specified class or interface."}

{"answer": "yes", "explanation": "PHP interfaces can declare static methods, which implementing classes must define as static."}

{"answer": "no", "explanation": "instanceof also returns true when an object implements the specified interface."}

{"answer":"no","explanation":"PHP interfaces only declare method signatures and cannot provide default implementations, unlike traits."}

{"answer": "yes", "explanation": "PHP allows abstract methods in abstract classes to be declared protected."}

{"answer": 3, "explanation": "Foo::cases() returns an array containing all three enum cases."}

{"answer":"yes","explanation":"Since PHP 8.2, traits may declare constants."}

{"answer":"yes","explanation":"In PHP 7+, both Exception and Error implement the Throwable interface."}

{"answer":"no","explanation":"TypeError extends Error, not Exception, so a catch (Exception $e) block will not catch it."}

{"answer": "no", "explanation": "The @ operator suppresses error messages, not exceptions."}

{"answer":"DivisionByZeroError","explanation":"intdiv() throws a DivisionByZeroError when the divisor is zero."}

{"answer":"no","explanation":"A finally block always runs, whether or not an exception is thrown or caught."}

{"answer":"no","explanation":"An exception thrown in a finally block overrides any return value or exception from the try block."}

{"answer":"yes","explanation":"Casting any object to bool returns true."}

{"answer": "yes", "explanation": "Registered shutdown functions are executed when the script terminates, including when exit() is called."}

{"answer": "no", "explanation": "A use statement only creates an alias; it does not load or autoload the class file."}

{"answer": "function", "explanation": "In PHP, you import a function with `use function namespace\\functionName;`."}

{"answer":"Controller/Api/UserController.php","explanation":"The App\\ prefix maps to src/, so the remaining namespace and class become Controller/Api/UserController.php."}

{"answer": "yes", "explanation": "Composer's vendor/autoload.php initializes and registers its autoloader using spl_autoload_register()."}

{"answer":"yes","explanation":"__NAMESPACE__ evaluates to the current namespace name as a string."}

{"answer":"no","explanation":"In a namespace, an unqualified class name in new is resolved relative to the current namespace, not the global root."}

{"answer": "yes", "explanation": "PSR-4 maps the App\\ prefix to src/, so App\\Model\\User corresponds to src/Model/User.php."}

{"answer":"no","explanation":"Namespace/class import use statements must be at the outermost scope (or namespace block), not inside a function body."}

{"answer":"yes","explanation":"In PHP, arrays are assigned by value (copy-on-write), not by reference."}

{"answer": 2, "explanation": "PHP arrays are copy-on-write and assigned by value, so appending to $b does not change $a."}

{"answer": "yes", "explanation": "Variables outside a function are global and are not directly accessible inside the function unless imported via global, $GLOBALS, or passed as parameters."}

{"answer":"no","explanation":"Unsetting $GLOBALS['x'] removes the global variable itself, not just within the function."}

{"answer":6,"explanation":"The function increments its by-reference argument, so $n becomes 6 before it is echoed."}

{"answer": "no", "explanation": "Foreach by value iterates over a copy (copy-on-write), so modifications to the array inside the loop are not reflected in the current iteration."}

{"answer":"no","explanation":"A static property belongs to the class itself, so changes are shared across all instances, not isolated per object."}

{"answer": "no", "explanation": "Boolean array keys are cast to integers (true becomes 1, false becomes 0), not stored as bool."}

{"answer": "yes", "explanation": "A generator can return a value, retrieved with getReturn() after iteration completes."}

{"answer":"no","explanation":"Generators in PHP are one-shot; rewind() cannot restart a generator that has already been consumed."}

{"answer":"yes","explanation":"In PHP, yield from delegates iteration to another generator, iterable, or array."}

{"answer":"Generator","explanation":"Calling a generator function returns an object of class Generator, so get_class() returns \"Generator\"."}

{"answer":3,"explanation":"The generator yields three values from the array, and iterator_to_array returns an array with three elements."}

{"answer":"no","explanation":"SplStack implements a LIFO stack, not a FIFO queue."}

{"answer":"yes","explanation":"ArrayIterator wraps an array and implements the Iterator interface for traversal."}

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

{"answer":"yes","explanation":"password_hash() automatically generates a secure salt, so no separate salt needs to be provided."}

{"answer":"no","explanation":"PASSWORD_DEFAULT uses bcrypt (not MD5), and password_hash handles salting automatically."}

{"answer": "yes", "explanation": "password_verify returns true when the password matches the hash."}

{"answer": "no", "explanation": "strip_tags removes HTML/PHP tags and does not prevent SQL injection; use prepared statements or escaping."}

{"answer": "yes", "explanation": "Regenerating the session ID on login prevents session fixation by issuing a new ID."}

{"answer": "php_sapi_name", "explanation": "The php_sapi_name() function returns the current Server API name, such as cli."}

{"answer": "yes", "explanation": "session_destroy() removes the server-side session data but leaves the session cookie in the browser unless it is explicitly deleted."}

{"answer": "no", "explanation": "Session data is only populated in $_SESSION after session_start() is called."}

{"answer":"8.4","explanation":"The array_find() function was introduced in PHP 8.4."}

{"answer":"yes","explanation":"Property hooks were introduced in PHP 8.4, allowing get/set hooks directly in property declarations."}

{"answer":"yes","explanation":"Asymmetric property visibility was introduced in PHP 8.4."}

{"answer":"8.5","explanation":"The #[\NoDiscard] attribute was introduced in PHP 8.5."}

{"answer":"8.5","explanation":"The pipe operator |> was introduced in PHP 8.5."}

{"answer":"8.5","explanation":"The clone-with syntax clone($obj, ['x' => 1]) was introduced in PHP 8.5."}

{"answer": "They do not exist in PHP core", "explanation": "PHP has array_key_first() and array_key_last() since 7.3, but no array_first() or array_last() functions."}

{"answer":"8.6","explanation":"The RFC Partial Function Application v2 was adopted for PHP 8.6."}

{"answer":"8.5","explanation":"The clamp_v2 RFC was implemented in PHP 8.5."}

{"answer":"no","explanation":"There is no adopted PHP RFC named “Context Managers v2” as of 2026-11-07."}

{"answer":"no","explanation":"No PHP RFC titled Bound-Erased Generic Types was declined in 2026."}

{"answer":"no","explanation":"The RFC to enable ZTS (multithreading) by default has not been accepted, so PHP still defaults to non-thread-safe builds."}

{"answer": "yes", "explanation": "PHP 8.5 still does not include native generics for parameterized types."}

{"answer":"yes","explanation":"PHP 8.5 would be the latest stable release before PHP 8.6's scheduled GA on 2026-11-19."}

{"answer": "yes", "explanation": "PHP 6 was abandoned, and the next major release after PHP 5.6 was PHP 7.0."}

{"answer": "yes", "explanation": "The RFC for the #[\Deprecated] attribute was accepted and implemented in PHP 8.4."}

{"answer": "yes", "explanation": "The dependency rule states that source code dependencies must point inward, so inner layers know nothing about outer layers."}

{"answer":"yes","explanation":"Domain entities should be framework-agnostic and depend only on the language and possibly the standard library, not Doctrine or Symfony."}

{"answer": "no", "explanation": "Controllers and Twig templates are presentation/interface-adapter concerns; calling use cases does not place them in the business-logic layer."}

{"answer":"Domain model","explanation":"The onion architecture places the domain model, containing business entities and rules, at its very center."}

{"answer": "yes", "explanation": "Deptrac can enforce layer dependency rules and fail builds when forbidden calls occur."}

{"answer": "no", "explanation": "Use cases should not depend on delivery mechanisms or ORM internals like HTTP requests or EntityManager; doing so couples business logic to infrastructure."}

{"answer":"Repository","explanation":"A repository provides a collection-like interface for accessing aggregates while hiding persistence details."}

{"answer":"yes","explanation":"In clean architecture, database details belong to the outer infrastructure layer, so replacing PostgreSQL should not affect domain or use-case code."}

{"answer": "no", "explanation": "An aggregate is a consistency boundary around related domain objects, not a database table."}

{"answer": "yes", "explanation": "Value objects are immutable and equality is based on their field values rather than object identity."}

{"answer": "aggregate root", "explanation": "In domain-driven design, the aggregate root is the only external entry point for modifying an aggregate."}

{"answer": "yes", "explanation": "Repositories are defined per aggregate root, not for every entity."}

{"answer": "yes", "explanation": "Ubiquitous language is a shared domain language used by developers and domain experts to keep the model consistent."}

{"answer":"universe of discourse","explanation":"The universe of discourse is the bounded context in which a model’s terms have consistent meaning, while outside it those terms can refer to different models."}

{"answer":"no","explanation":"DDD favors rich domain models with behavior, not anemic getter/setter objects."}

{"answer":"yes","explanation":"A bounded context defines its own model, so the same real-world concept can be represented by different classes in different contexts."}

{"answer":"yes","explanation":"Symfony's DI container instantiates services only when they are first requested, not when the container is built."}

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

{"answer":"no","explanation":"Symfony autowiring can automatically inject dependencies and register services without manually declaring every service in services.yaml."}

{"answer": "yes", "explanation": "Twig compiles templates into PHP classes and caches them for reuse across requests."}

{"answer": "yes", "explanation": "In Symfony's dev/debug environment, the container is cached and only rebuilt when tracked container resources change."}

{"answer":"APP_ENV","explanation":"Symfony reads the APP_ENV environment variable to determine the active environment (e.g., dev or prod)."}

{"answer":"no","explanation":"Symfony controller actions must be public; the router cannot invoke a private method."}

{"answer": "no", "explanation": "Event subscribers are just listeners registered through getSubscribedEvents; they do not automatically receive events before other listeners, as ordering depends on priority and registration order."}

{"answer":"yes","explanation":"Symfony 6.0 removed the deprecated Guard component in favor of authenticator classes implementing AuthenticatorInterface."}

{"answer": "IsGranted", "explanation": "The #[IsGranted] attribute enforces role/permission checks on controller methods and returns 403 when unmet."}

{"answer":"yes","explanation":"Symfony voters vote on whether a user has permission for an attribute, optionally against a specific object passed to isGranted()."}

{"answer":"yes","explanation":"Symfony 7 removed Doctrine annotation support for validation, so constraints must use PHP attributes."}

{"answer":"yes","explanation":"Symfony forms enable CSRF protection by default and validate the token on submission unless explicitly disabled."}

{"answer": "yes", "explanation": "Symfony validates submitted forms on the server regardless of any client-side HTML5 validation."}

{"answer":"make:form","explanation":"The Symfony MakerBundle command make:form generates a new FormType class."}

{"answer": "no", "explanation": "Symfony does not store the user's plain-text password in the session; it stores authentication state and typically a token, not credentials."}

{"answer": "yes", "explanation": "Symfony applications typically place bundle configuration in config/packages, often split by bundle or topic."}

{"answer":"yes","explanation":"This matches Symfony's convention of committing .env defaults while keeping .env.local uncommitted for real secrets."}

{"answer":"debug:container","explanation":"The Symfony `debug:container` command lists registered services and their aliases."}

{"answer":"no","explanation":"Symfony's compiled container is frozen, so calling setParameter() at runtime from a controller throws instead of changing parameters."}

{"answer":"no","explanation":"Since Symfony 4, services are private by default and cannot be fetched directly from the container."}

{"answer":"no","explanation":"Bundles can work without a config file in config/packages; configuration is only needed when defaults must be changed."}

{"answer":"yes","explanation":"Symfony configuration supports the %env(VAR)% syntax to inject environment variable values."}

{"answer":"APP_DEBUG","explanation":"Symfony uses the APP_DEBUG environment variable to enable debug mode."}

{"answer":"no","explanation":"Symfony Messenger supports multiple handlers for the same message, and they are all invoked unless an exception occurs."}

{"answer": "no", "explanation": "The sync transport handles the message immediately in the same process; it does not queue it for a worker."}

{"answer": "messenger:consume", "explanation": "The messenger:consume console command starts a worker that consumes messages from a Messenger transport."}

{"answer": "yes", "explanation": "In Symfony Messenger, retry_strategy is configured per transport under the transport options."}

{"answer":"no","explanation":"Symfony Messenger uses PhpSerializer by default, not JSON serialization."}

{"answer":"yes","explanation":"Symfony Scheduler generates messages according to a schedule and dispatches them via Messenger."}

{"answer": "Doctrine", "explanation": "Symfony Messenger's Doctrine transport persists messages in database tables via Doctrine."}

{"answer":"yes","explanation":"Symfony Messenger lets you register custom middleware in the bus middleware chain, and their order relative to built-in middleware can be controlled by configuration."}

{"answer":"yes","explanation":"Symfony follows a six-month minor release cycle in May and November, with major releases every two years."}

{"answer":"8.4","explanation":"Symfony 8 requires PHP 8.4 or higher."}

{"answer":"no","explanation":"Symfony 7.0 removed support for docblock annotations, requiring PHP attributes instead."}

{"answer": "yes", "explanation": "Symfony AssetMapper uses importmap.php to manage CSS/JS without Node.js or Webpack."}

{"answer":"no","explanation":"Symfony 6.4 is a Long-Term Support (LTS) release, so the statement is false."}

{"answer": "no", "explanation": "Symfony removes deprecated features in the next major release, so deprecations from the previous branch do not keep working."}

{"answer": "yes", "explanation": "Symfony provides an UPGRADE guide for each major release documenting backward-incompatible changes."}

{"answer":"AssetMapper","explanation":"Symfony's AssetMapper component handles assets and importmaps without Node.js or Webpack."}

{"answer":"no","explanation":"Symfony 8.2 is scheduled for release in late November 2026, so it has not been released as of 2026-11-07."}

{"answer":"yes","explanation":"Symfony follows a six-month minor release cycle, so after 8.1 in May 2026, 8.2 is scheduled for November 2026."}

{"answer":"8.2","explanation":"Symfony follows a six-month release cycle, so 8.2 is the next version after 8.1."}

{"answer":"no","explanation":"Symfony 8.2 would be a minor release, not a major release requiring applications to be rewritten."}

{"answer":"yes","explanation":"PHP minor releases like 8.1 to 8.2 aim to preserve backward compatibility, though deprecations may appear."}

{"answer":"8.4","explanation":"Symfony 8.4 LTS is the final 8.x minor release, arriving alongside Symfony 9.0."}

{"answer":"no","explanation":"Symfony minor releases keep the same PHP requirement as their major release, so Symfony 8.2 will still require PHP 8.4, not 8.5."}

{"answer":"yes","explanation":"Symfony's deprecation policy keeps 8.x deprecations until the next major version, 9.0."}

{"answer": "no", "explanation": "Twig does not allow arbitrary PHP code; it provides its own limited expression syntax and functions."}

{"answer":"yes","explanation":"Twig enables autoescaping by default, so printed variables are escaped automatically."}

{"answer": "yes", "explanation": "The Twig e filter escapes a value for safe output, defaulting to HTML context."}

{"answer":"format_number","explanation":"The IntlExtra Twig extension provides the format_number filter to format numbers according to a locale."}

{"answer": "yes", "explanation": "The raw filter marks a value as safe so auto-escaping is not applied."}

{"answer":"yes","explanation":"Twig uses {{ }} for output expressions and {% %} for executing tags such as conditions, loops, and set."}

{"answer": "no", "explanation": "Twig allows declaring variables in templates using the set tag, not only controller-provided values."}

{"answer":"dump","explanation":"The Twig dump() function displays a variable's debug structure when the debug extension is enabled."}

{"answer":"yes","explanation":"Bootstrap is a CSS/JS UI component library, not a single-page application framework."}

{"answer": ".container", "explanation": "The .container class provides a responsive fixed-width container whose max width changes at each breakpoint."}

{"answer": "no", "explanation": "Bootstrap's grid uses 12 columns, and modern versions use flexbox rather than floats."}

{"answer":"yes","explanation":"Bootstrap 5 defines five named breakpoints: sm, md, lg, xl, and xxl."}

{"answer":"no","explanation":"Bootstrap's spacing utilities map numbers to fractions or multiples of $spacer (e.g., 3 = $spacer), not simply the number times $spacer."}

{"answer": "data-bs-toggle", "explanation": "Bootstrap 5 uses the data-bs-toggle attribute to initialize interactive components like dropdowns."}

{"answer": "yes", "explanation": "Bootstrap 5 removed the jQuery dependency and its components are written in vanilla JavaScript."}

{"answer": "no", "explanation": "Bootstrap 5.3 enables dark mode via data-bs-theme=\"dark\" on the root element, not a .dark class."}

{"answer": "no", "explanation": "Doctrine ORM does not create tables automatically at runtime; schema must be created via schema tools or migrations."}

{"answer":"persist","explanation":"EntityManager::persist() marks a new entity as managed and defers SQL until flush()."}

{"answer": "no", "explanation": "Doctrine ORM 3 removed EntityManager::merge(), so it no longer exists."}

{"answer":"yes","explanation":"DQL operates on entity classes and their mapped fields rather than database tables and columns."}

{"answer":"null","explanation":"Doctrine's Repository::find() returns null when no matching record exists."}

{"answer": "no", "explanation": "DoctrineBundle does not automatically call flush() at the end of a request; persistence requires explicit flushing."}

{"answer": "yes", "explanation": "Doctrine's Unit of Work tracks changes to managed entities, so flush() persists updates without calling persist() again."}

{"answer": "no", "explanation": "remove() only marks the entity for deletion; the DELETE SQL is executed on flush()."}

{"answer":"no","explanation":"PostgreSQL MVCC allows readers and writers to operate concurrently without blocking each other."}

{"answer": "EXPLAIN", "explanation": "The EXPLAIN command displays a query's execution plan without running the query."}

{"answer":"no","explanation":"SERIAL is a PostgreSQL pseudo-type using a sequence default, while GENERATED ... AS IDENTITY is the SQL-standard identity mechanism with different semantics."}

{"answer": "no", "explanation": "By default PostgreSQL treats NULLs as distinct, so a UNIQUE constraint permits multiple rows with NULL in the column."}

{"answer": "string_agg", "explanation": "PostgreSQL's string_agg aggregate function concatenates string values using a specified separator."}

{"answer": "no", "explanation": "Plain VACUUM only marks dead tuple space as reusable within the database; VACUUM FULL returns it to the OS."}

{"answer":"PARTITION BY","explanation":"The PARTITION BY clause divides rows into groups for the window function."}

{"answer":"no","explanation":"READ COMMITTED prevents dirty reads but allows non-repeatable reads, so it does not protect against them."}

{"answer": "yes", "explanation": "PostgreSQL runs each statement in its own implicit transaction unless explicitly using BEGIN or an autocommit-off mode."}

{"answer": "COMMIT", "explanation": "COMMIT ends a transaction and permanently saves its changes."}

{"answer":"yes","explanation":"Indexes can speed up UPDATE and DELETE statements that locate rows using an indexed column in their search condition."}

{"answer": "yes", "explanation": "SAVEPOINT lets you roll back to a point within a transaction without aborting the entire transaction."}

{"answer": "no", "explanation": "EXPLAIN ANALYZE actually executes the query and shows the plan with runtime statistics."}

{"answer":"pgvector","explanation":"The pgvector extension provides vector data types and indexes for embedding similarity search in PostgreSQL."}

{"answer": "yes", "explanation": "A partial index includes only table rows that satisfy the specified WHERE predicate."}

{"answer": "no", "explanation": "PostgreSQL implements SERIALIZABLE using Serializable Snapshot Isolation with predicate locks, not by locking the rows a transaction reads."}

{"answer":"yes","explanation":"HTTP 201 Created indicates the request successfully created a new resource."}

{"answer": 204, "explanation": "HTTP 204 No Content indicates success with no response body."}

{"answer": "yes", "explanation": "DELETE is idempotent because repeating it on the same resource should not change the intended outcome, even if later requests may return 404."}

{"answer":"no","explanation":"Access-Control-Allow-Origin is a response header sent by the server, not by the client."}

{"answer": "yes", "explanation": "HTTP 429 indicates the client has sent too many requests in a given amount of time."}

{"answer":"no","explanation":"It is the reverse: 4xx codes indicate client errors and 5xx codes indicate server-side errors."}

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

{"answer":"yes","explanation":"RFC 5789 states PATCH is neither safe nor idempotent, whereas PUT is idempotent."}

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

{"answer": "yes", "explanation": "CSRF tokens are session-bound secrets issued by the server and validated server-side on state-changing requests such as POST."}

{"answer":"Content-Security-Policy","explanation":"The CSP is delivered via the Content-Security-Policy HTTP response header."}

{"answer":"no","explanation":"OAuth 2.0 is an authorization framework, and an access token grants access rather than reliably identifying the user."}

{"answer":"no","explanation":"XSS is primarily prevented by context-aware output encoding/escaping, not merely by validating input before database storage."}

{"answer":"code","explanation":"The authorization server redirects to the redirect_uri with a code parameter, which the client exchanges for an access token."}

{"answer": "yes", "explanation": "Refresh tokens are long-lived credentials used 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 stored alongside the hash and only needs to be unique."}

{"answer": "no", "explanation": "PHPUnit test classes must extend PHPUnit\\Framework\\TestCase (or a subclass); simply having test methods is not enough."}

{"answer": "no", "explanation": "setUp() runs before each test method, while setUpBeforeClass() runs once before all tests."}

{"answer": "no", "explanation": "A data provider supplies one or more argument sets, so it is not limited to exactly one."}

{"answer": "expectException", "explanation": "PHPUnit's expectException() declares that a specified exception class should be thrown."}

{"answer": "no", "explanation": "It is reversed: stubs return canned data, while mocks verify method calls."}

{"answer":"yes","explanation":"PHPUnit 10 recommends the #[DataProvider] attribute, and doc-comment annotations like @dataProvider are deprecated."}

{"answer": "no", "explanation": "PHPUnit supports test dependencies via @depends, allowing one test to depend on another's result."}

{"answer": "--order-by=random", "explanation": "PHPUnit's --order-by=random option runs tests in random order."}

{"answer":"3-3","explanation":"intdiv(7, 2) is 3 and intdiv(-7, 2) is -3, concatenated as \"3-3\"."}

{"answer": -9, "explanation": "The exponentiation operator has higher precedence than unary minus, so it evaluates as -(3 ** 2)."}

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

{"answer":"other","explanation":"In PHP 8, the loose comparison 'a' == 0 is false, so the default case runs and prints 'other'."}

{"answer":"2c","explanation":"strtr() with an array replaces the longest matching substring first, so 'ab' becomes '2', leaving 'c'."}

{"answer":"[hello]","explanation":"A negative start beyond the string length is treated as 0, so substr returns the whole string."}

{"answer":"k,n,m","explanation":"The array union keeps the left-hand value for duplicate key 'k' and appends only new keys from the right array, so keys are k, n, m."}

{"answer":"yxz","explanation":"Sorting by the third column puts 'y' first, then 'x' and 'z' retain their original order under stable usort, yielding 'yxz'."}

{"answer":4,"explanation":"String-keyed array unpacking passes named arguments, so a=5 and b=1, returning 4."}

{"answer": 3, "explanation": "The first-class callable captures the object, so the closure still calls g() on the original P instance and returns 3."}

{"answer": "B", "explanation": "Late static binding makes static::class resolve to the runtime class B."}

{"answer":10,"explanation":"Inside the set hook, assigning to $this->x writes the backing value directly, so it becomes 5 * 2 = 10."}

{"answer":"BA","explanation":"TB::f wins for f() returning B, and TA::f is aliased as g() returning A, so concatenation is BA."}

{"answer":0,"explanation":"Each class using the trait gets its own static property, so CY::$n remains 0."}

{"answer": 2, "explanation": "A return in the finally block overrides the return value from the try block."}

{"answer":"second","explanation":"The exception thrown in the finally block overrides the original RuntimeException and is caught by the outer LogicException handler."}

{"answer":"App\\Foo|Baz","explanation":"Baz::class resolves through the import to App\\Foo, while \\Baz::class refers to the global class Baz."}

{"answer":"noyes","explanation":"class_exists('Foo') checks the global class, while class_exists('Ns\\Foo') finds the namespaced class."}

{"answer":"1,2,99","explanation":"The reference $v remains bound to the last array element, so assigning 99 changes $a[2] to 99."}

{"answer": 3, "explanation": "In PHP 8.1+, the inherited method shares its static variable across A and B, so the three calls increment it to 3."}

{"answer":11,"explanation":"send(10) assigns 10 to $x at the first yield, so the generator returns 10 + 1."}

{"answer":"ok,2","explanation":"yield from returns inner's return value 'ok', but the final yield reuses key 0 and overwrites the first value when iterator_to_array preserves keys."}

{"answer": "noyes", "explanation": "The first check matches the hash cost and prints no, while the second higher cost needs rehash and prints yes."}

{"answer":"strict-out","explanation":"In PHP 8.5, E_ALL no longer includes the E_STRICT bit (2048), so the bitwise AND is 0."}

{"answer":"mapped","explanation":"Symfony maps the HTTP_X_TOKEN server variable to the X-Token header, and HeaderBag lookup is case-insensitive/normalized."}

{"answer":"BCA","explanation":"Listeners run by descending priority: B (10), C (5), then A (default 0)."}

{"answer": "same", "explanation": "Doctrine's identity map returns the already-managed User instance for repeated finds of the same ID."}

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

{"answer": 1, "explanation": "COUNT(column) counts only non-NULL values, so it counts the single value 1."}

{"answer":"10,30,60","explanation":"The window sum computes cumulative totals 10, 30, and 60, which string_agg concatenates in id order."}

{"answer":"M1M2","explanation":"Symfony Messenger middleware run in the configured order, so Trace('M1') echoes before Trace('M2')."}

{"answer": 11, "explanation": "The HandleMessageMiddleware invokes every handler registered for Ping, so 1 + 10 is added to $n."}

{"answer": 1, "explanation": "The first insert adds one row, and the second conflicts on the unique index and does nothing."}

{"answer": 2, "explanation": "The deferrable unique constraint is not checked until commit, so both duplicate rows exist during the transaction and count(*) returns 2."}

{"answer": 6, "explanation": "The filter matches both test_sum and test_sum_abs, each with 3 data provider cases, for 6 tests total."}

{"answer":"1,1","explanation":"PHPUnit 10 requires data providers to be static, so the non-static prov() causes the single data-provider test to error."}

{"answer": "POST", "explanation": "curl uses the POST method by default when data is supplied with -d."}

{"answer":"GET","explanation":"The -G option makes curl append the -d data to the URL as a query string and send a GET request."}

{"answer":"invalid_client","explanation":"RFC 6749 specifies invalid_client when client authentication fails, including an unknown client_id."}

{"answer":"fragment","explanation":"With response_type=token, the access token is returned in the URI fragment of the redirect_uri."}

{"answer":6,"explanation":"The default filter treats false as empty, returning 2, and 2 * 3 equals 6."}

{"answer":"Twig\\Error\\RuntimeError","explanation":"The ~ operator binds tighter than +, so ('a' ~ 1) + 2 raises a PHP TypeError that Twig wraps as a RuntimeError."}

{"answer": 0, "explanation": "The array [''] is not considered blank by NotBlank, so there are no violations."}

{"answer":"Symfony\\Component\\Form\\Exception\\LogicException","explanation":"Calling isValid() on an unsubmitted form throws Symfony's Form LogicException, and get_class() prints its fully qualified class name."}

{"answer":"same","explanation":"Public services are shared by default, so both get('a') calls return the same instance."}

{"answer":"hi Bob!","explanation":"During compilation, Symfony resolves nested parameter placeholders, so '%greeting%!' becomes 'hi Bob!'."}

{"answer": "960px", "explanation": "Bootstrap 5.3 sets .container max-width to 960px at the lg breakpoint (≥992px)."}

{"answer":"text-danger","explanation":"Both classes have equal specificity, and Bootstrap generates text-danger after text-primary, so text-danger wins."}

{"answer": 2, "explanation": "The Domain class depends on Application and Infrastructure classes, violating Domain → Domain only in two places."}

{"answer": 3, "explanation": "The Domain class depends on three non-Domain types: PlaceOrder, Db, and Logger."}

{"answer":"10,15","explanation":"The method returns a new Money object with 15, while $a remains 10, so the output is 10,15."}

{"answer":1,"explanation":"The remove call throws before unsetting because there is only one item, and the catch leaves the item intact, so count remains 1."}

{"answer":"hi","explanation":"In PHP 8.5, `new C()->hi()` is valid and calls `hi()`, which returns 'hi'."}

{"answer":"yesno","explanation":"The lazy ghost is uninitialized before accessing $o->v (prints yes), then initializes after the access (prints no)."}

{"answer":"no","explanation":"The Guard component's AbstractGuardAuthenticator was removed in Symfony 6, so the class does not exist in 8.1."}

{"answer":"noyes","explanation":"Symfony 8.1 removed AnnotationClassLoader but still provides AttributeClassLoader, so the echoes produce \"no\" then \"yes\"."}