Карта знаний PHP — anthropic/claude-haiku-5.5, run-07 · think: low

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

{"answer": "yes", "explanation": "The ?? operator behaves like isset(), so it suppresses undefined variable, index, and property notices and returns the right operand when the left is unset or null."}

{"answer": "ab", "explanation": "echo accepts multiple comma-separated arguments and prints each one in order with no separator, so 'a' and 'b' print as ab."}

{"answer": "yes", "explanation": "In PHP, print is a language construct that always returns 1, so it can be used within an expression."}

{"answer": "no", "explanation": "The elvis operator returns its left operand when it is truthy, and otherwise returns the right operand."}

{"answer": "yes", "explanation": "PHP 8 gave arithmetic addition and subtraction higher precedence than the concatenation operator, so \"Sum: \" . 1 + 2 evaluates as \"Sum: \" . 3."}

{"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": "sum: 5", "explanation": "In PHP 8, the concatenation operator '.' has lower precedence than '+', so 2 + 3 is evaluated first as 5 and then concatenated with 'sum: '."}

{"answer": "no", "explanation": "With ===, arrays are equal only if they have the same key/value pairs in the same order and of the same types; with == element order doesn't matter."}

{"answer": "no", "explanation": "0 == false is a loose comparison, and it evaluates to true because both operands convert to boolean false; strict comparison would be 0 === false, which is false."}

{"answer": "no", "explanation": "PHP 8 changed string-to-number comparison: a non-numeric string like \"abc\" is compared as a string with 0, so \"abc\" == 0 is false."}

{"answer": "yes", "explanation": "In PHP, null loosely equals 0, the empty string, and false (null == 0, null == \"\", and null == false all evaluate to true)."}

{"answer": 42, "explanation": "PHP's (int) cast on a string takes the leading numeric portion and ignores the trailing non-numeric characters, so '42abc' becomes 42."}

{"answer": 10, "explanation": "In PHP, the '+' operator converts the numeric string '5' to an integer, so '5' + 5 evaluates to the integer 10."}

{"answer": "no", "explanation": "In PHP, casting false to a string produces an empty string \"\", not \"0\"; it is true (1) that becomes \"1\", and null also becomes \"\"."}

{"answer": "yes", "explanation": "0.1 + 0.2 evaluates to approximately 0.30000000000000004 in binary floating point, which is not exactly equal to 0.3, so the strict comparison returns false."}

{"answer": "no", "explanation": "strrev() reverses a string byte by byte, so multibyte UTF-8 characters get broken into invalid sequences."}

{"answer": "yes", "explanation": "str_contains() returns true when the needle 'world' is found within the haystack 'Hello world'."}

{"answer": "no", "explanation": "str_pad() accepts a STR_PAD_LEFT, STR_PAD_RIGHT (the default), or STR_PAD_BOTH argument, so it can pad on either side or both."}

{"answer": "no", "explanation": "By default, PHP's trim() strips spaces, tabs, newlines, carriage returns, NUL bytes, and vertical tabs (\\x0B), not just spaces."}

'héllo' has 5 characters, but é is 2 bytes in UTF-8, so total bytes = 6. ⏎  ⏎ {"answer": 6, "explanation": "strlen counts bytes, and the accented é encodes as two bytes in UTF-8, giving 6 bytes total for the 5-character string."}

{"answer": "def", "explanation": "A negative start position counts from the end of the string, so -3 begins at the third-to-last character and returns the rest: 'def'."}

{"answer": "no", "explanation": "PHP's ucfirst() returns a new string with the first character uppercased and does not modify the original string passed to it, since PHP strings are passed by value to built-in functions."}

{"answer": "yes", "explanation": "Heredoc strings support variable interpolation like double-quoted strings, while nowdoc strings are literal like single-quoted strings and do not interpolate variables."}

{"answer": "no", "explanation": "PHP's sort() discards the original keys and reindexes the array numerically from 0; asort() or uasort() preserve key associations."}

{"answer": "yes", "explanation": "PHP converts canonical decimal integer strings used as array keys, such as '5', into integer keys, so '5' is stored as 5."}

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

{"answer": "yes", "explanation": "Without a callback, array_filter() keeps only truthy values, so falsy elements such as 0, '', null, false, and empty arrays are removed."}

{"answer": "no", "explanation": "By default, array_slice() reindexes numeric keys starting from 0; the preserve_keys parameter defaults to false and must be set to true to keep the original numeric keys."}

{"answer": [20, 30], "explanation": "array_slice starts at index 1 and takes 2 elements, giving 20 and 30, and re-indexes them from 0."}

{"answer": 2, "explanation": "The + operator takes the union of the arrays: key 'a' comes from the left array, and only the new key 'b' is added from the right, giving 2 elements."}

{"answer": "yes", "explanation": "PHP 8.1 added support for unpacking arrays with string keys using the spread operator, where later string keys overwrite earlier ones."}

{"answer": "no", "explanation": "PHP 8.0+ allows named arguments alongside argument unpacking, such as foo(...$positional, named: 1), so the statement is false."}

{"answer": "no", "explanation": "In PHP, a closure declared without a use clause cannot access variables from the enclosing scope; it only sees its own parameters and superglobals."}

{"answer": 3, "explanation": "func_num_args() returns the number of arguments passed to the function, which is 3 here even though only one parameter is declared."}

{"answer": "no", "explanation": "Arrow function bodies in curly braces are statement blocks, not expression lists, and they require return to produce a value; a body with a single expression can omit the braces."}

{"answer": "no", "explanation": "PHP arrow functions capture outer variables by value at the time the arrow function is created, not by reference or lazily at use time."}

{"answer": "yes", "explanation": "A static closure cannot bind $this automatically from its defining context, so it does not capture $this, and trying to bind an object to it produces a warning."}

{"answer": 5, "explanation": "The closure captures $x by value at creation time, when $x was 5, so later reassignment to 7 does not affect it."}

{"answer": "yes", "explanation": "Without strict_types, PHP coerces the numeric string \"5\" to the integer 5 when passed to an int parameter."}

{"answer": "yes", "explanation": "Constructor property promotion, introduced in PHP 8.0, lets you declare and assign properties directly in the constructor parameter list using visibility modifiers like private."}

{"answer": "final", "explanation": "Declaring a method as final prevents child classes from overriding it."}

{"answer": "yes", "explanation": "PHP's final keyword prevents a subclass from overriding the method, and attempting to do so causes a fatal error."}

{"answer": "no", "explanation": "Private properties are only accessible within the class that declares them, so a subclass cannot access them directly (protected properties would be accessible)."}

{"answer": "class@anonymous", "explanation": "PHP names anonymous classes with a 'class@anonymous' prefix, followed by a NUL byte, the file path, and an offset; a plain `new class {}` has no parent, so the prefix is just 'class'."}

{"answer": "yes", "explanation": "PHP does not treat private methods as overridable, so a child class can declare a method with the same name and any visibility without a fatal error."}

{"answer": "no", "explanation": "__get() is also called when accessing inaccessible properties, such as private or protected ones from outside the class, not just non-existent ones."}

{"answer": "Error", "explanation": "Modifying an initialized readonly property throws an Error, not an Exception, because it is a compile-time-enforced runtime error in the Error hierarchy."}

{"answer": "yes", "explanation": "PHP interfaces can declare constants, which implementing classes inherit and can access but cannot override (prior to PHP 8.1 overriding was disallowed; since 8.1 they can be overridden only if not final)."}

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

{"answer": "yes", "explanation": "PHP interfaces can declare static methods, and implementing classes must provide them with a compatible static signature."}

{"answer": "no", "explanation": "The instanceof operator also returns true when an object's class implements the named interface, not just when it inherits from a class."}

{"answer": "no", "explanation": "PHP interface methods cannot have a body or default implementation; they are only signatures, while traits are the mechanism that provides method implementations."}

{"answer": "yes", "explanation": "Abstract methods may be declared public or protected, but not private, since a private method cannot be overridden by child classes."}

{"answer": 3, "explanation": "Foo::cases() returns an array of all enum cases, and this enum declares three cases: A, B, and C."}

{"answer": "yes", "explanation": "Traits cannot declare constants before PHP 8.2, but PHP 8.2 added support for constants in traits."}

{"answer": "yes", "explanation": "In PHP 7 and later, Throwable is the base interface implemented by both the Exception and Error classes."}

{"answer": "no", "explanation": "TypeError extends Error, not Exception, so catch (Exception $e) will not catch it; both Error and Exception implement Throwable separately."}

{"answer": "no", "explanation": "The @ operator only silences PHP error messages (warnings, notices, deprecations) by temporarily setting error_reporting to 0; it does not catch or suppress thrown exceptions."}

{"answer": "DivisionByZeroError", "explanation": "intdiv() throws a DivisionByZeroError when the divisor is 0, as it does for the % operator."}

{"answer": "no", "explanation": "In PHP, the finally block runs whether or not an exception was thrown or caught, including when no exception occurs or when an exception is uncaught."}

{"answer": "no", "explanation": "An exception thrown in a finally block replaces any exception or return value pending from the try block, so it does affect the outcome."}

Objects cast to bool are always true in PHP, so the result is true. For a result question, the answer should be yes/no or a number/string; true corresponds to "yes". ⏎  ⏎ {"answer": "yes", "explanation": "Any object, including an Exception instance, casts to boolean true in PHP."}

{"answer": "yes", "explanation": "PHP runs registered shutdown functions after script execution ends, including when exit() is called, and also after fatal errors."}

{"answer": "no", "explanation": "A use statement only creates an alias for a class name at compile time; it does not load or autoload the class file, which happens only when the class is actually referenced at runtime."}

{"answer": "function", "explanation": "In PHP, the 'use function' statement imports a function name into the current namespace, while 'use const' imports constants."}

{"answer": "src/Controller/Api/UserController.php", "explanation": "PSR-4 maps the namespace prefix App\\ to src/, so the remaining namespace segments Controller\\Api become directories and the class name becomes the filename with .php appended."}

{"answer": "yes", "explanation": "Composer's vendor/autoload.php loads autoload_real.php, which calls spl_autoload_register() to register Composer's class loader."}

{"answer": "yes", "explanation": "__NAMESPACE__ is a PHP magic constant that evaluates to the name of the current namespace as a string."}

{"answer": "no", "explanation": "An unqualified class name in `new` is resolved relative to the current namespace (or via `use` imports), not from the global root; only a leading `\` makes it fully qualified."}

{"answer": "yes", "explanation": "PSR-4 maps the namespace prefix App\\ to the src/ directory, so the remaining namespace segment Model\\User becomes the path src/Model/User.php."}

{"answer": "no", "explanation": "In PHP, `use` statements for importing namespaces are only allowed at the top level of a file or inside a namespace block, not inside a function body, which causes a parse error."}

{"answer": "yes", "explanation": "In PHP, arrays are assigned by value, so `$b = $a` creates a copy (implemented with copy-on-write), and changes to one don't affect the other."}

{"answer": 2, "explanation": "PHP arrays are copied by value on assignment, so appending to $b does not affect $a, which still has two elements."}

{"answer": "yes", "explanation": "In PHP, global variables are not visible inside functions by default, so they must be accessed via the global keyword, the $GLOBALS array, or passed as parameters."}

{"answer": "no", "explanation": "unset($GLOBALS['x']) removes the global variable itself, so it is gone everywhere, not just within that function."}

{"answer": 6, "explanation": "The parameter $x is passed by reference, so incrementing it inside inc() changes the original $n from 5 to 6."}

{"answer": "no", "explanation": "A foreach loop by value iterates over a copy of the array (copy-on-write), so changes made to the array inside the loop are not seen during that pass."}

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

{"answer": "no", "explanation": "PHP casts boolean array keys to integers, so true is stored as the integer key 1, not as a bool."}

{"answer": "yes", "explanation": "Since PHP 7.0, a generator can use return with a value, which is retrieved after the generator completes via $gen->getReturn()."}

{"answer": "no", "explanation": "PHP generators cannot be rewound after they have advanced past their first yield; calling rewind() on a fully consumed generator throws an Exception."}

{"answer": "yes", "explanation": "The yield from expression delegates iteration to a sub-generator or any iterable, passing values through to the caller."}

{"answer": "Generator", "explanation": "Calling a function containing yield returns a Generator object, so get_class returns the class name \"Generator\"."}

{"answer": 3, "explanation": "`yield from [1, 2, 3]` yields three values with keys 0, 1, 2, and `iterator_to_array` preserves those keys, producing a three-element array."}

{"answer": "no", "explanation": "SplStack is a LIFO (last in, first out) structure; the FIFO queue behavior belongs to SplQueue."}

{"answer": "yes", "explanation": "ArrayIterator implements the Iterator interface (and related interfaces like ArrayAccess and Countable), letting you wrap an array and traverse it with foreach or iterator methods."}

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

{"answer": "yes", "explanation": "PHP's password_hash() automatically generates a cryptographically secure random salt and embeds it in the resulting hash, so passing a salt manually is unnecessary (and the old salt option was removed in PHP 8)."}

{"answer": "no", "explanation": "PASSWORD_DEFAULT currently maps to bcrypt (PASSWORD_BCRYPT), not md5, and salts are generated automatically by password_hash()."}

{"answer": "yes", "explanation": "password_hash creates a salted hash of 'secret', and password_verify checks the plaintext against it, returning true."}

{"answer": "no", "explanation": "strip_tags() removes HTML and PHP tags, which addresses XSS-style concerns but does nothing to prevent SQL injection; use prepared statements or parameterized queries instead."}

{"answer": "yes", "explanation": "Calling session_regenerate_id() after login issues a new session ID, preventing an attacker's pre-set session ID from being reused to hijack the authenticated session."}

{"answer": "php_sapi_name", "explanation": "php_sapi_name() returns the server API (SAPI) name the PHP process is running under, such as \"cli\" or \"apache2handler\"."}

{"answer": "yes", "explanation": "session_destroy() removes the session data stored on the server but does not expire the session cookie in the browser, which must be cleared separately with setcookie()."}

{"answer": "no", "explanation": "Without calling session_start() (or having session.auto_start enabled), PHP does not load session data, so $_SESSION is not populated."}

{"answer": "8.4", "explanation": "array_find() was added in PHP 8.4 as part of the new array search helpers alongside array_find_key(), array_any(), and array_all()."}

{"answer": "yes", "explanation": "Property hooks, which let get and set logic be declared directly within a property declaration, were introduced in PHP 8.4."}

{"answer": "yes", "explanation": "Asymmetric property visibility, such as public private(set), was introduced in PHP 8.4 and lets the read and write visibility of a property differ."}

{"answer": "8.5", "explanation": "The #[\\NoDiscard] attribute was added in PHP 8.5, warning when the return value of a marked function is discarded."}

{"answer": "8.5", "explanation": "The pipe operator |> was not included in PHP 8.4 and was added in PHP 8.5, after earlier proposals for 8.4 were dropped."}

{"answer": 8.5, "explanation": "The clone-with syntax was added in PHP 8.5, and I'm not fully certain of that version number."}

{"answer": "8.5", "explanation": "The array_first() and array_last() functions were added in PHP 8.5, following an accepted RFC for that release."}

{"answer": "none", "explanation": "The Partial Function Application v2 RFC was not adopted into any PHP version; PHP 8.1 instead added first-class callable syntax via a separate RFC."}

{"answer": "none", "explanation": "I don't know of a PHP version that implemented a clamp() function from a clamp_v2 RFC, so I believe none has, though my knowledge may be incomplete for 2026."}

{"answer": "no", "explanation": "I have no record of the Context Managers v2 RFC being adopted into PHP, and I can't verify events as late as 2026-11-07, so I can't confirm this claim."}

{"answer": "no", "explanation": "I have no record of a PHP RFC titled 'Bound-Erased Generic Types' being declined in 2026, so I can't confirm the statement is true."}

{"answer": "no", "explanation": "I am not aware of any accepted RFC making ZTS (thread-safe builds) the default in PHP, and my knowledge may not cover events up to 2026-11-07, so this is unverified."}

{"answer": "yes", "explanation": "PHP 8.5 does not add generics; the language still has no parameterized types, and prior generics proposals were not accepted."}

{"answer": "yes", "explanation": "PHP 8.5 was released in November 2025, and the next version, 8.6, is scheduled for November 2026, so it wouldn't be out as of 2026-11-07, though I can't verify the exact 2026-11-19 date."}

{"answer": "yes", "explanation": "PHP 6 was abandoned in development (its Unicode work was dropped), and the next major release after PHP 5.6 was PHP 7.0."}

{"answer": "yes", "explanation": "The #[\\Deprecated] attribute RFC was accepted and implemented in core PHP, letting developers mark functions and other elements as deprecated."}

{"answer": "yes", "explanation": "In clean and onion architectures, source-code dependencies point inward, so inner layers (entities, use cases) have no knowledge of outer layers (frameworks, UI, database)."}

{"answer": "yes", "explanation": "Domain entities should be framework-agnostic, depending only on the PHP language and possibly its standard library, with no Doctrine or Symfony imports."}

{"answer": "no", "explanation": "Controllers and Twig templates belong to the presentation (UI/infrastructure) layer, not the business-logic layer; they merely invoke use cases that live in the application or domain layer."}

{"answer": "Domain Model", "explanation": "In onion architecture, the domain model (entities and domain logic) forms the innermost core, with all other layers depending inward toward it."}

{"answer": "yes", "explanation": "Tools like deptrac analyze class dependencies against configured layer rules and report or fail the build when a forbidden dependency exists."}

{"answer": "no", "explanation": "Clean architecture says use cases should not depend on frameworks or infrastructure like HTTP requests or EntityManager; they should receive plain input data and depend on abstractions such as repository interfaces."}

{"answer": "Repository", "explanation": "A Repository provides an in-memory-like collection interface for aggregates or entities while abstracting away the underlying persistence mechanism."}

{"answer": "yes", "explanation": "In clean architecture, the domain and use cases depend only on abstractions (ports/interfaces), so the database is an outer-layer detail that can be swapped by changing its adapter implementation."}

{"answer": "no", "explanation": "In Domain-Driven Design, an aggregate is a cluster of domain objects treated as a single unit for data changes, with a root entity enforcing consistency; it is not the same as a database table, though it may be persisted across one or more tables."}

{"answer": "yes", "explanation": "A Value Object is defined by its attribute values, is immutable, and equality is based on those values rather than object identity."}

{"answer": "Aggregate Root", "explanation": "The aggregate root is the single entity through which all external access and state changes to the aggregate must pass, enforcing its invariants."}

{"answer": "yes", "explanation": "In Domain-Driven Design, repositories are defined per aggregate root, since the root is the only entry point for accessing and modifying objects within the aggregate."}

{"answer": "yes", "explanation": "In Domain-Driven Design, the ubiquitous language is the shared vocabulary, built from the domain model, used by both developers and domain experts."}

{"answer": "domain of discourse", "explanation": "The domain (universe) of discourse is the set of objects within which a model's language has a consistent interpretation, and outside which the same expressions can denote different things."}

{"answer": "no", "explanation": "Domain-Driven Design recommends rich domain models where behavior and invariants live in entities and value objects; anemic models with logic pushed into services are considered an anti-pattern."}

{"answer": "yes", "explanation": "In Domain-Driven Design, a bounded context defines a boundary within which a particular model applies, so the same real-world concept (e.g., a 'Customer') can have different representations and classes in different contexts."}

{"answer": "yes", "explanation": "Symfony's DI container instantiates services only when they are first requested, unless a service is explicitly marked as eager or is needed by another service earlier."}

{"answer": "php bin/console debug:router", "explanation": "The debug:router command lists all registered routes in a Symfony application (in Symfony 4+; older versions used debug:router as well)."}

{"answer": "no", "explanation": "Symfony's autowiring and autoconfiguration let services be registered automatically from the src directory via the resource loading in services.yaml, so manual declaration of every service is not required."}

{"answer": "yes", "explanation": "Twig compiles templates into PHP classes, which are stored in a cache directory and reused across requests until the template changes."}

{"answer": "yes", "explanation": "In dev, Symfony's kernel uses ConfigCache to check the freshness of the compiled container against tracked resource files, rebuilding it only when those files change."}

{"answer": "APP_ENV", "explanation": "Symfony reads the APP_ENV environment variable (typically set in .env) to determine the active environment such as dev or prod."}

{"answer": "no", "explanation": "Symfony controllers must be public methods; the router and controller resolver cannot invoke private or protected methods, so the statement is false."}

{"answer": "no", "explanation": "Event subscribers are registered as ordinary listeners, so their execution order depends only on priority values, not on being a subscriber, and no interface grants them precedence over listeners."}

{"answer": "yes", "explanation": "Symfony 5.1 introduced the authenticator system, and Symfony 6.0 removed the deprecated Guard authenticators, so authentication is now built on AuthenticatorInterface."}

{"answer": "IsGranted", "explanation": "The #[IsGranted] attribute (Symfony\\Component\\Security\\Http\\Attributes\\IsGranted) checks a role or permission on a controller method and throws an AccessDeniedException (403) if it fails."}

{"answer": "yes", "explanation": "Symfony voters evaluate whether a user has a given attribute (such as EDIT) on a specific subject object, which is what isGranted('EDIT', $post) triggers."}

{"answer": "yes", "explanation": "Symfony 7 declares validation constraints via PHP attributes, and annotation-based configuration (including Doctrine annotations) is no longer supported in Symfony's components."}

{"answer": "yes", "explanation": "Symfony forms enable CSRF protection by default (the csrf_protection option defaults to true), adding and validating a hidden _token field on submission."}

{"answer": "yes", "explanation": "Symfony form validation is enforced on the server via constraints, so it runs regardless of any client-side HTML5 validation that may have passed."}

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

{"answer": "no", "explanation": "Symfony's security component stores only the user identifier (and serialized user data without the plain password) in the session, and passwords are hashed rather than kept in plain text."}

{"answer": "yes", "explanation": "Symfony stores bundle configuration in YAML, XML, or PHP files under config/packages, typically one file per bundle or topic."}

{"answer": "yes", "explanation": "This matches the common Symfony convention, where .env holds committed dev defaults and .env.local, which is git-ignored, overrides them with real secrets."}

{"answer": "debug:container", "explanation": "The Symfony console command `php bin/console debug:container` lists all registered services along with their aliases."}

{"answer": "no", "explanation": "Once the Symfony container is compiled its ParameterBag is frozen, so calling setParameter() at runtime throws a LogicException, and parameters should be set through configuration instead."}

{"answer": "no", "explanation": "Since Symfony 4.0, services are private by default, so they can't be fetched directly from the container unless explicitly marked public or accessed via a service locator."}

{"answer": "no", "explanation": "Configuration is optional for most Symfony bundles, which provide default values, so they work without a file in config/packages."}

{"answer": "yes", "explanation": "Symfony's DI container resolves the %env(VAR)% syntax in configuration files such as services.yaml to the value of the named environment variable."}

{"answer": "APP_DEBUG", "explanation": "Symfony uses the APP_DEBUG environment variable (set to 1 or true) to toggle debug mode, which enables the profiler and Twig debugging features."}

{"answer": "no", "explanation": "Symfony Messenger allows a single message to be routed to multiple handlers, since each matching handler is invoked for the message."}

{"answer": "no", "explanation": "The sync transport in Symfony Messenger handles messages immediately in the same process without queuing them for a worker, unlike async transports."}

{"answer": "php bin/console messenger:consume", "explanation": "The Symfony Messenger component provides the messenger:consume command to start a worker that processes queued messages."}

{"answer": "yes", "explanation": "In Symfony Messenger, retry_strategy (max_retries, delay, multiplier, etc.) is set under each individual transport's configuration, so it applies per transport."}

{"answer": "yes", "explanation": "Since Symfony 5.3, Messenger's default serializer is the Symfony Serializer configured to use the JSON format, replacing the older PHP serializer default."}

{"answer": "yes", "explanation": "Symfony Scheduler triggers messages on a defined schedule, and those messages are then dispatched through the Messenger component."}

{"answer": "doctrine", "explanation": "Symfony Messenger's Doctrine transport (doctrine://) stores messages in a database table using Doctrine DBAL."}

{"answer": "yes", "explanation": "Symfony Messenger buses accept custom middleware in their configured middleware list, which can be positioned before or after the built-in middleware."}

{"answer": "yes", "explanation": "Symfony ships a major version every two years and a minor version every six months, with minor releases in May and November."}

```json ⏎ {"answer": "8.4", "explanation": "Symfony 8.0 raises the minimum requirement to PHP 8.4, up from PHP 8.2 for Symfony 7.4."} ⏎ ```

{"answer": "no", "explanation": "Symfony 7.0 removed support for docblock annotations, so routes, validation, and other config must use PHP attributes instead (annotations were deprecated in 6.x)."}

{"answer": "yes", "explanation": "Symfony AssetMapper serves and versions CSS and JS without Node.js, npm, or Webpack, and uses importmap.php to map JavaScript module dependencies."}

{"answer": "no", "explanation": "Symfony 6.4 is a long-term support (LTS) release, receiving bug fixes for three years and security fixes for four, so the statement is false."}

{"answer": "no", "explanation": "Symfony major releases remove features that were deprecated in the previous major branch, which is why deprecations must be fixed before upgrading."}

{"answer": "yes", "explanation": "Symfony publishes UPGRADE-X.0.md files for each major version, documenting breaking changes and the steps needed to upgrade."}

{"answer": "AssetMapper", "explanation": "Symfony's AssetMapper component serves and versions assets and manages JavaScript importmaps without needing Node.js or Webpack."}

{"answer": "no", "explanation": "Symfony releases minor versions every six months, and Symfony 8.0 is scheduled for around November 2026, so 8.2 would not be released until about late 2027."}

{"answer": "no", "explanation": "Symfony 8.0 is due in May 2026, so the November 2026 minor release would be 8.1, and 8.2 would follow in May 2027."}

{"answer": "8.2", "explanation": "Symfony releases minor versions in May and November each year, so the minor release after 8.1 (November 2026) is 8.2, due around May 2027."}

{"answer": "no", "explanation": "Symfony minor releases like 8.2 are backward-compatible and do not introduce breaking changes; only major releases such as 8.0 can require code changes."}

{"answer": "no", "explanation": "PHP minor releases aim for backward compatibility, but 8.1 to 8.2 introduced deprecations (such as dynamic property creation) and some edge-case breaks, so code changes can be needed."}

{"answer": 4, "explanation": "Symfony majors typically end with a x.4 minor release (as with 5.4, 6.4 and 7.4), so 8.4 should be the last 8.x minor before 9.0."}

{"answer": "no", "explanation": "Symfony minor releases generally keep the same minimum PHP version as their major release, so 8.2 would not normally raise the requirement to PHP 8.5."}

{"answer": "yes", "explanation": "Symfony's backward compatibility policy only removes deprecated features in the next major version, so anything deprecated in 8.x can't be removed before 9.0."}

{"answer": "no", "explanation": "Twig expressions inside {{ }} use Twig's own expression syntax, and they can only call functions, filters, and methods that are explicitly exposed to the template, not arbitrary PHP code."}

{"answer": "yes", "explanation": "Twig's autoescape option is enabled by default, so printed variables are escaped for HTML context unless a filter such as raw is applied."}

{"answer": "yes", "explanation": "The Twig `e` filter is an alias of `escape`, which defaults to the HTML strategy and escapes special characters for safe HTML output."}

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

{"answer": "yes", "explanation": "In Twig, the raw filter marks a value as safe, so auto-escaping is not applied to it."}

{"answer": "yes", "explanation": "In Twig, {{ }} outputs the result of an expression, while {% %} is used for tags such as if, for, and set that control logic."}

{"answer": "no", "explanation": "Twig lets you declare variables inside a template with the {% set %} tag, so values do not have to come only from the controller."}

{"answer": "dump", "explanation": "Twig's dump() function outputs debugging information about a variable, such as its structure for arrays and objects, and requires the debug extension to be enabled."}

{"answer": "yes", "explanation": "Bootstrap is a front-end library providing CSS styles and JavaScript UI components, not a single-page application framework like React or Angular."}

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

{"answer": "no", "explanation": "Bootstrap's grid uses 12 columns per row, not 16, and since version 4 it is built on flexbox rather than floats."}

{"answer": "yes", "explanation": "Bootstrap 5 uses sm, md, lg, xl, and xxl as infixes in class names; xs has no infix because it applies by default."}

{"answer": "no", "explanation": "The number is a key into the spacing scale map, not a direct multiplier: in Bootstrap 5, .mt-3 maps to $spacer (1rem), and .px-2 maps to $spacer * .5."}

{"answer": "data-bs-toggle", "explanation": "In Bootstrap 5, the data-bs-toggle attribute activates interactive components such as dropdowns, modals, and collapses on an element."}

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

{"answer": "no", "explanation": "Bootstrap 5.3 enables dark mode with a data-bs-theme=\"dark\" attribute on the root element (or a component), not a .dark class."}

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

{"answer": "persist", "explanation": "EntityManager::persist() marks an entity as managed so it will be inserted on the next flush(), with no SQL executed at the time of the call."}

{"answer": "no", "explanation": "EntityManager::merge() was deprecated in Doctrine ORM 2.7 and removed in ORM 3.0, so it no longer exists in that version."}

{"answer": "yes", "explanation": "DQL (Doctrine Query Language) is written against PHP entity classes and their properties rather than database tables and columns."}

{"answer": null, "explanation": "Doctrine's find() returns null when no entity matches the given identifier."}

{"answer": "no", "explanation": "Doctrine's EntityManager does not flush automatically at the end of a request; changes must be persisted explicitly by calling flush() (DoctrineBundle does not add an automatic flush)."}

{"answer": "yes", "explanation": "Doctrine's Unit of Work tracks managed entities, so changes to them are detected and written on flush() without calling persist() again."}

{"answer": "no", "explanation": "In Doctrine's EntityManager, remove() only schedules the entity for deletion, and the SQL DELETE runs when flush() is called."}

{"answer": "no", "explanation": "PostgreSQL's MVCC means readers do not block writers and writers do not block readers, since readers see a snapshot of committed data while writers create new row versions."}

{"answer": "EXPLAIN", "explanation": "EXPLAIN displays the query's execution plan without actually running the query (unlike EXPLAIN ANALYZE, which executes it)."}

{"answer": "no", "explanation": "SERIAL is a PostgreSQL shorthand that creates a sequence and a nextval() default, while GENERATED ... AS IDENTITY is the SQL-standard column property with stricter rules, such as GENERATED ALWAYS blocking explicit values unless OVERRIDING is used."}

{"answer": "no", "explanation": "In PostgreSQL, NULL values are considered distinct from one another, so a UNIQUE constraint allows multiple rows with NULL by default (NULLS NOT DISTINCT is needed to restrict this, in PostgreSQL 15+)."}

{"answer": "string_agg", "explanation": "PostgreSQL's string_agg(expression, delimiter) concatenates non-null input values into one string, separated by the given delimiter."}

{"answer": "no", "explanation": "Plain VACUUM marks space from dead tuples as reusable within the table but generally does not return it to the operating system; only VACUUM FULL or similar rewrites do that."}

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

{"answer": "no", "explanation": "READ COMMITTED only prevents dirty reads; non-repeatable reads are prevented starting at REPEATABLE READ (or higher)."}

{"answer": "yes", "explanation": "PostgreSQL runs each standalone SQL statement in its own implicit transaction, committed automatically unless an explicit transaction block is used."}

{"answer": "COMMIT", "explanation": "The COMMIT statement ends the current transaction and makes all of its changes permanent."}

{"answer": "yes", "explanation": "UPDATE and DELETE statements with WHERE clauses on indexed columns can locate target rows quickly via the index instead of scanning the whole table."}

{"answer": "yes", "explanation": "PostgreSQL supports savepoints, and ROLLBACK TO SAVEPOINT undoes only the statements executed after that savepoint within the transaction."}

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

{"answer": "pgvector", "explanation": "The pgvector extension adds a vector data type and indexes (IVFFlat and HNSW) for similarity search over embeddings in PostgreSQL."}

{"answer": "yes", "explanation": "A partial index contains entries only for table rows that satisfy its WHERE predicate, which makes it smaller and cheaper to maintain."}

{"answer": "no", "explanation": "PostgreSQL implements SERIALIZABLE using Serializable Snapshot Isolation (SSI), which tracks read/write dependencies with predicate locks and aborts transactions on conflicts rather than locking the rows read."}

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

{"answer": 204, "explanation": "HTTP 204 No Content indicates the request succeeded and there is no content in the response body, commonly used after DELETE."}

{"answer": "yes", "explanation": "RFC 7231 (section 4.2.2) classifies DELETE as idempotent, meaning repeated identical requests leave the server state the same, although the response status may differ (for example, 204 then 404)."}

{"answer": "no", "explanation": "Access-Control-Allow-Origin is a response header sent by the server to tell the browser which origins may read the response; the client sends the Origin header, not this one."}

{"answer": "yes", "explanation": "HTTP status 429 Too Many Requests indicates the user has sent too many requests in a given time window, typically exceeding a rate limit."}

{"answer": "no", "explanation": "It is reversed: 4xx status codes indicate client errors, while 5xx codes indicate server-side errors."}

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

{"answer": "yes", "explanation": "RFC 5789 states that PATCH is neither safe nor idempotent, whereas PUT is required to be idempotent under RFC 7231."}

{"answer": "no", "explanation": "A plain == comparison can leak timing information, so hash comparisons should use hash_equals() or, better, password_verify()."}

{"answer": "yes", "explanation": "A session-bound CSRF token generated by the server and validated on state-changing requests like POST is the standard defense against cross-site request forgery."}

{"answer": "Content-Security-Policy", "explanation": "The Content-Security-Policy HTTP response header enables and defines the Content Security Policy for a page."}

{"answer": "no", "explanation": "OAuth 2.0 is an authorization framework, not an authentication protocol; the access token grants access to resources and does not itself identify the user (OpenID Connect adds the identity layer via ID tokens)."}

{"answer": "no", "explanation": "XSS is prevented by context-aware output encoding/escaping when rendering data, not merely by validating input before storage, since data can enter the page through many paths and the correct escaping depends on the output context."}

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

{"answer": "yes", "explanation": "Refresh tokens have a longer lifetime than access tokens and are used to obtain new access tokens without requiring the user to re-authenticate."}

{"answer": "no", "explanation": "Salts are stored alongside the hash and are not secret; their purpose is to defeat precomputed rainbow tables, and verification uses the stored salt."}

{"answer": "no", "explanation": "PHPUnit only collects test methods from classes that extend PHPUnit\\Framework\\TestCase (or provide a suite() method), so extending TestCase is required."}

{"answer": "no", "explanation": "PHPUnit's setUp() runs before each individual test method, not once before all tests in the class; setUpBeforeClass() is the method that runs once per class."}

{"answer": "no", "explanation": "A PHPUnit data provider supplies multiple argument sets, and the test runs once for each set, not just one."}

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

{"answer": "no", "explanation": "It is the reverse: a stub only returns canned data without verifying calls, while a mock records and verifies which methods were invoked."}

{"answer": "yes", "explanation": "PHPUnit 10 and later favor the #[DataProvider] attribute, and the older @dataProvider docblock annotation is deprecated."}

{"answer": "no", "explanation": "PHPUnit supports test dependencies through the @depends annotation or #[Depends] attribute, which let one test use the result of another."}

{"answer": "--order-by=random", "explanation": "PHPUnit's --order-by option with the random value runs tests in random order (also accepts --random-order and --random-order-seed)."}

intdiv(7,2) = 3. intdiv(-7,2) truncates toward zero = -3. Concatenation gives "3" . "-3" = "3-3". ⏎  ⏎ {"answer": "3-3", "explanation": "intdiv truncates toward zero, so intdiv(7,2) is 3 and intdiv(-7,2) is -3; concatenating gives \"3-3\"."}

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

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

{"answer": "other", "explanation": "In PHP 8, 'a' == 0 is false because the non-numeric string is compared as a string with \"0\", so the default branch runs (PHP 7 would have printed 'zero')."}

{"answer": "2c", "explanation": "When strtr is given an array, it replaces the longest matching key first, so 'ab' becomes '2' and the remaining 'c' is unchanged."}

{"answer": "[hello]", "explanation": "A negative start longer than the string is clamped to 0, so substr returns the whole string 'hello' and it is wrapped in brackets."}

{"answer": "k,n,m", "explanation": "The + operator keeps all keys from $a and adds only keys from $b that are missing, so the keys are k, n, then m."}

{"answer": "yxz", "explanation": "usort sorts by the third element ascending, giving [2,'y',1] first, then [1,'x',2] and [3,'z',2] in their original order since PHP 8's sort is stable, so the column-1 values join to \"yxz\"."}

Spread with string keys maps to named parameters: a=5, b=1, so 5-1=4. ⏎  ⏎ {"answer": 4, "explanation": "String keys in an argument unpack are treated as named arguments, so a=5 and b=1, giving 5 - 1 = 4."}

{"answer": 3, "explanation": "The first-class callable `$p->g(...)` holds a reference to the original object, so setting `$p = null` does not destroy it, and `$f()` returns `$this->v`, which is 3."}

{"answer": "B", "explanation": "static::class resolves to the late static binding class of the called object, which is B, so it outputs \"B\"."}

{"answer": 10, "explanation": "The set hook stores $value * 2 (10) directly into the backing property, which bypasses the hook due to the recursion guard, and with no get hook the read returns 10."}

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

{"answer": 0, "explanation": "A static property declared in a trait is copied into each class that uses it, so CX and CY each have their own $n; setting CX::$n to 1 leaves CY::$n at its default of 0."}

{"answer": 2, "explanation": "A return statement in the finally block overrides the return value from the try block, so f() returns 2."}

{"answer": "second", "explanation": "The LogicException thrown in the finally block replaces the RuntimeException, so the outer catch receives it and echoes its message."}

{"answer": "App\\Foo|Baz", "explanation": "`Baz::class` resolves through the `use App\\Foo as Baz` import to `App\\Foo`, while `\\Baz::class` is the fully qualified global name `Baz`."}

{"answer": "noyes", "explanation": "class_exists('Foo') looks up the global class Foo, which doesn't exist, so it returns 'no'; class_exists('Ns\\Foo') finds the namespaced class, so it returns 'yes'."}

{"answer": "1,2,99", "explanation": "After the by-reference foreach, $v still references the last element $a[2], so assigning $v = 99 overwrites it."}

{"answer": 3, "explanation": "Since PHP 8.1, an inherited method shares its static variables with the parent, so $n goes 1, 2, 3 across the three calls."}

{"answer": 11, "explanation": "Calling send(10) on an unstarted generator first runs it to the first yield, then resumes it with 10 as that yield's result, so $x is 10 and it returns 10 + 1 = 11."}

{"answer": "ok,2", "explanation": "yield from keeps inner's keys 0 and 1 (values 1 and 2), then outer's own auto-key 0 yields 'ok', overwriting key 0 in iterator_to_array, leaving [0=>'ok', 1=>2]."}

{"answer": "noyes", "explanation": "The first check returns false because the hash already uses cost 4, and the second returns true because the target cost of 5 differs, so the echoes print 'no' then 'yes'."}

{"answer": "strict-in", "explanation": "E_ALL is 32767 in PHP 8.x and includes E_STRICT (2048), so E_ALL & 2048 is 2048, which is not 0, and the ternary returns 'strict-in'."}

{"answer": "mapped", "explanation": "Symfony's ServerBag::getHeaders() turns HTTP_X_TOKEN into the header X-Token, and HeaderBag lookups are case-insensitive, so get('X-Token') returns 'abc'."}

{"answer": "BCA", "explanation": "Symfony runs listeners in descending priority order: B (10), then C (5), then A (0, the default)."}

{"answer": "same", "explanation": "Doctrine's identity map returns the same managed instance for repeated find() calls on the same ID, so $a and $b are the same object (and in fact the same as $u)."}

{"answer": 0, "explanation": "Removing an entity that was persisted but not yet flushed just cancels the pending insert, so no row is ever written to users."}

{"answer": 1, "explanation": "count(x) counts only non-NULL values, and the table holds one non-NULL value (1) and one NULL."}

{"answer": "10,30,60", "explanation": "The running sum over id (default frame) gives 10, 30, 60 for ids 1, 2, 3, and string_agg joins them in id order with commas."}

{"answer": "M1M2", "explanation": "The bus runs the first middleware, which echoes M1 and calls next(); the second echoes M2, then the stack's no-op terminal middleware returns the envelope without further output."}

{"answer": 11, "explanation": "HandleMessageMiddleware calls every handler registered for Ping, since the aliases 'h1' and 'h2' differ and nothing is skipped, so $n becomes 1 + 10 = 11."}

{"answer": 1, "explanation": "The unique index makes the second INSERT of value 1 hit a conflict, which ON CONFLICT DO NOTHING silently skips, so only one row remains."}

{"answer": 2, "explanation": "The UNIQUE constraint is deferrable and deferred, so the duplicate insert doesn't fail until commit, and the uncommitted transaction's SELECT sees both rows."}

{"answer": 6, "explanation": "The filter `test_sum` is a substring regex match, so it selects `test_sum` (3 data sets) and `test_sum_abs` (3 data sets), while `test_other` is excluded."}

```json ⏎ {"answer": "2, 1", "explanation": "The data provider yields two cases, and only the case with input -1 fails the assertTrue($x > 0) check."} ⏎ ```

{"answer": "POST", "explanation": "Using curl's -d (--data) option with no explicit -X flag makes curl send the request as a POST."}

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

{"answer": "invalid_client", "explanation": "RFC 6749 Section 5.2 defines invalid_client for failed client authentication, which includes an unknown client."}

{"answer": "fragment", "explanation": "With response_type=token (implicit grant), the authorization server appends the access_token to the redirect_uri in the URL fragment (after #), not the query string."}

{"answer": 6, "explanation": "The default filter returns 2 because false counts as empty in Twig, and 2 * 3 gives 6."}

{"answer": "Twig\\Error\\RuntimeError", "explanation": "Twig's '~' binds tighter than '+', so 'a' ~ 1 yields \"a1\", and \"a1\" + 2 throws a TypeError in PHP 8, which Twig wraps in a RuntimeError."}

{"answer": 0, "explanation": "NotBlank only fails for null, false, empty strings, or empty arrays, and `['']` is a non-empty array, so no violation is raised and count returns 0."}

```json ⏎ {"answer": "invalid", "explanation": "Form::isValid() returns false when the form has not been submitted, so no exception is thrown and the ternary echoes 'invalid'."} ⏎ ```

{"answer": "same", "explanation": "Services registered with the default shared setting return the same instance on every get() call, so both spl_object_id values match."}

{"answer": "hi Bob!", "explanation": "Compile resolves placeholders recursively: %greeting% becomes 'hi %name%', which then becomes 'hi Bob', so the message is 'hi Bob!'."}

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

{"answer": "text-danger", "explanation": "Both utilities use `color` with `!important` and equal specificity, so the one defined later in Bootstrap's generated CSS wins; `text-danger` comes after `text-primary` in the theme color order."}

{"answer": 2, "explanation": "The Domain layer may only depend on Domain, but OrderService references PlaceOrder (Application) and Db (Infrastructure), giving two violations."}

{"answer": 3, "explanation": "The Domain class depends on PlaceOrder (Application), Db (Infrastructure), and the fully qualified Logger (Infrastructure), and Domain may only depend on Domain, so each of these three references is a violation."}

{"answer": "10,15", "explanation": "The add method returns a new Money instance without modifying the original, so $a stays 10 and $c becomes 15."}

{"answer": 1, "explanation": "remove('a') throws because the order holds only one item, so the item is never unset and count() still returns 1."}

{"answer": "hi", "explanation": "PHP 8.5 allows calling a method directly on a `new` expression without wrapping it in parentheses, so `new C()->hi()` returns 'hi'."}

{"answer": "yesno", "explanation": "The lazy ghost starts uninitialized, so the first check prints 'yes'; reading $o->v runs the initializer, which makes the object initialized, so the second check prints 'no'."}

{"answer": "no", "explanation": "AbstractGuardAuthenticator was deprecated in Symfony 5.3 and removed in 6.0, so class_exists() returns false and the ternary echoes 'no'."}

{"answer": "noyes", "explanation": "AnnotationClassLoader was removed in Symfony 7.0, so class_exists returns false, while AttributeClassLoader still exists in 8.1, so it returns true."}