Карта знаний PHP — anthropic/claude-haiku-5.5, run-11 · think: low

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

{"answer": "yes", "explanation": "The ?? operator uses isset() semantics internally, so undefined variables, array keys, and properties produce no notice or warning and simply fall through to the right-hand value."}

{"answer": "ab", "explanation": "PHP's echo accepts multiple comma-separated arguments and outputs each in sequence 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 expressions, unlike echo."}

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

{"answer": "yes", "explanation": "In PHP 8, the concatenation operator (.) was given lower precedence than + and -, so arithmetic is evaluated before concatenation."}

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

{"answer": "sum: 5", "explanation": "In PHP 8, the arithmetic `+` binds tighter than the concatenation operator `.`, so `2 + 3` is evaluated first as 5, 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; == ignores order, but === does not."}

{"answer": "no", "explanation": "0 == false is a loose comparison that performs type juggling and evaluates to true; the strict comparison 0 === false would return false."}

{"answer": "no", "explanation": "PHP 8 changed string-to-number comparison: a non-numeric string like \"abc\" is compared as a string with 0 (converted to \"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 are all true), even though 0 and \"\" are not loosely equal to each other in PHP 8."}

{"answer": 42, "explanation": "PHP's integer cast of a string reads the leading numeric portion and ignores the trailing non-numeric characters, yielding 42."}

{"answer": 10, "explanation": "PHP converts the numeric string '5' to an integer in arithmetic, so '5' + 5 yields the integer 10."}

{"answer": "no", "explanation": "In PHP, false cast to string becomes an empty string \"\", not \"0\"; it is null-like, while true becomes \"1\"."}

{"answer": "yes", "explanation": "In PHP, 0.1 + 0.2 evaluates to about 0.30000000000000004 due to binary floating-point representation, so the strict comparison with 0.3 returns false."}

{"answer": "no", "explanation": "strrev() reverses by bytes, not characters, so multibyte UTF-8 characters get their bytes scrambled and produce invalid output."}

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

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

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

'héllo' has 5 characters, but é is two bytes in UTF-8 (C3 A9), so total bytes = 6. ⏎  ⏎ {"answer": 6, "explanation": "strlen counts bytes, and the 'é' character occupies 2 bytes in UTF-8, so 'h' + 2 bytes + 'llo' totals 6 bytes."}

{"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 of the string."}

{"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."}

{"answer": "yes", "explanation": "Heredoc strings behave like double-quoted strings and interpolate variables, while nowdoc strings behave like single-quoted strings and do not."}

{"answer": "no", "explanation": "PHP's sort() removes the existing keys and reindexes the array with sequential numeric keys; asort() preserves key-to-value association."}

{"answer": "yes", "explanation": "PHP converts numeric string keys that are canonical decimal integers, 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 elements that evaluate to true, so falsy values 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 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; it re-indexes the result from 0."}

{"answer": 2, "explanation": "The `+` operator merges arrays by key, keeping the left value for 'a' and adding 'b', giving ['a' => 1, 'b' => 2] with 2 elements."}

{"answer": "yes", "explanation": "PHP 8.1 added support for unpacking arrays with string keys in array literals, so [...$a, ...$b] now works with associative arrays."}

{"answer": "no", "explanation": "PHP 8.1+ allows named arguments alongside unpacking, e.g. `foo(...$positional, name: 'x')` or `foo(...['a' => 1])`, as long as named arguments come after positional ones."}

{"answer": "no", "explanation": "In PHP, a closure without a use clause cannot access variables from the enclosing scope; they must be imported with use (arrow functions being the exception, which capture by value automatically)."}

{"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": "PHP arrow functions (fn) take a single expression as their body and do not support a curly-brace block with multiple statements."}

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

{"answer": "yes", "explanation": "A static closure cannot bind $this automatically from its defining scope, so it does not capture $this, and attempting to use $this inside it causes an error."}

{"answer": 5, "explanation": "The closure captures $x by value when it is created, so later reassignment of $x to 7 does not affect the captured value of 5."}

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

{"answer": "yes", "explanation": "Constructor property promotion, introduced in PHP 8.0, lets visibility modifiers on constructor parameters automatically declare and assign the corresponding properties."}

{"answer": "final", "explanation": "Declaring a method with the final keyword prevents subclasses from overriding it."}

{"answer": "yes", "explanation": "In PHP, declaring a method as final prevents child classes from overriding it, 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 a parent's private property directly."}

{"answer": "class@anonymous", "explanation": "PHP names anonymous classes with the prefix class@anonymous (or ParentName@anonymous if it extends a parent), followed by a NUL byte and the file path and offset."}

{"answer": "yes", "explanation": "In PHP, private methods are not overridden by child classes, so a child can declare a same-named method with any visibility without a conflict."}

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

{"answer": "Error", "explanation": "Reassigning an initialized readonly property throws an Error (Error: Cannot modify readonly property), not an Exception."}

{"answer": "yes", "explanation": "PHP interfaces can declare constants, which implementing classes inherit and can access, though they cannot be overridden by implementers before PHP 8.1 (final constants in 8.1+ control overriding)."}

{"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 method signatures, and implementing classes must define them with compatible signatures."}

{"answer": "no", "explanation": "PHP's instanceof operator also returns true when an object's class implements the interface being checked, 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 can be declared public or protected, but not private, since subclasses must be able to implement them."}

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

{"answer": "yes", "explanation": "Traits can declare constants since PHP 8.2; earlier versions did not allow constants in traits."}

{"answer": "yes", "explanation": "In PHP 7 and later, Throwable is an interface implemented by both the Exception and Error classes, making it their common ancestor."}

{"answer": "no", "explanation": "TypeError implements the Throwable interface and extends Error, not Exception, so catch (Exception $e) will not catch it."}

{"answer": "no", "explanation": "The @ operator only suppresses PHP error messages such as warnings and notices by temporarily setting error_reporting; it does not catch or suppress thrown exceptions."}

intdiv(5, 0) throws DivisionByZeroError in PHP 7 and later. ⏎  ⏎ {"answer": "DivisionByZeroError", "explanation": "intdiv() throws a DivisionByZeroError when the divisor is zero, as do the / and % operators in PHP 7+."}

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

{"answer": "no", "explanation": "An exception thrown in a finally block replaces the try block's outcome, discarding any pending exception or return value from the try or catch."}

Casting any object to bool in PHP yields true (objects are always truthy, regardless of their properties). ⏎  ⏎ {"answer": "yes", "explanation": "Objects always cast to true in PHP, so casting an Exception object to bool gives true."}

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

{"answer": "no", "explanation": "The use statement only creates an alias for a fully qualified 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, `use function Namespace\\functionName;` imports a function, while `use const` imports constants and plain `use` imports classes."}

{"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 file name with a .php extension."}

{"answer": "no", "explanation": "Including vendor/autoload.php does not itself register autoloaders; it loads Composer's autoload file, which in turn calls spl_autoload_register() (via ClassLoader::register) to register the loader, so the statement is misleadingly incomplete rather than strictly accurate."}

{"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 an imported `use` alias), not from the global root; only a leading `\` forces global resolution."}

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

{"answer": "no", "explanation": "PHP's `use` import statements must appear at the top level of a file or inside a namespace block, not inside a function body; `use` inside a function only applies to closure variable binding."}

{"answer": "yes", "explanation": "In PHP, arrays are assigned by value, so assigning an array to a new variable creates a copy (implemented via copy-on-write), unlike objects, which are assigned by handle."}

{"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 automatically visible inside functions, so they must be accessed via the global keyword, $GLOBALS array, or passed as parameters."}

{"answer": "no", "explanation": "Since PHP 8.1, $GLOBALS is a read-only copy, but unset($GLOBALS['x']) still removes the global variable itself for all code, not just the function."}

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

{"answer": "no", "explanation": "A by-value foreach iterates over a copy of the array, so changes made to the original 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 becomes key 1 and is not stored as a bool."}

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

{"answer": "no", "explanation": "PHP generators cannot be rewound after they have advanced past the first yield; calling rewind() then throws an Exception 'Cannot rewind a generator that was already run'."}

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

{"answer": "Generator", "explanation": "Calling a function that contains yield returns an instance of the built-in Generator class, so get_class returns its name."}

{"answer": 3, "explanation": "The generator yields the three array elements via yield from, and iterator_to_array preserves their keys 0, 1, 2 with no collisions, so the count is 3."}

{"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 SeekableIterator, Traversable and Iterator interfaces, letting you wrap an array (or object) and iterate over it with foreach or Iterator methods."}

{"answer": "no", "explanation": "ArrayObject implements IteratorAggregate (and Traversable), 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 no separate salt needs to be supplied (and the old salt option is deprecated/removed)."}

{"answer": "no", "explanation": "PASSWORD_DEFAULT currently refers to the bcrypt algorithm (and may change over time), not md5, which is not suitable for password hashing."}

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

{"answer": "no", "explanation": "strip_tags() removes HTML and PHP tags for output sanitization; it does not protect against SQL injection, which requires prepared statements or parameterized queries."}

{"answer": "yes", "explanation": "Calling session_regenerate_id() after login issues a new session ID, preventing an attacker's fixed session ID from being reused by the authenticated user."}

{"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 the session cookie remains in the browser unless it is explicitly expired, for example with setcookie()."}

{"answer": "no", "explanation": "Without session_start() (or 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 functions alongside array_find_key(), array_any(), and array_all()."}

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

{"answer": "yes", "explanation": "PHP 8.4 introduced asymmetric visibility, allowing separate read and write visibility such as public private(set) for properties."}

{"answer": "8.5", "explanation": "The #[\\NoDiscard] attribute, which warns when a function's return value is ignored, was added in PHP 8.5."}

{"answer": "8.5", "explanation": "The pipe operator |> was accepted for PHP 8.5 after earlier proposals, and it was not part of PHP 8.4."}

{"answer": "8.5", "explanation": "The clone-with feature, which lets clone() take an array of property overrides, was added in PHP 8.5."}

{"answer": "8.5", "explanation": "array_first() and array_last() were added in PHP 8.5, as part of the array helper functions introduced with that release."}

{"answer": "none", "explanation": "As far as I know, the Partial Function Application v2 RFC was not adopted into any PHP version, so no version applies."}

{"answer": 8.5, "explanation": "The clamp_v2 RFC targeted PHP 8.5, the release after 8.4, though I'm not certain it was ultimately accepted."}

{"answer": "no", "explanation": "I have no record of a 'Context Managers v2' RFC being adopted into PHP, and I can't verify events up to the stated date, so I assume it has not been adopted."}

{"answer": "no", "explanation": "I'm not aware of any PHP RFC titled 'Bound-Erased Generic Types' being declined in 2026, and I can't verify that this event occurred."}

{"answer": "no", "explanation": "I'm not aware of any accepted RFC making ZTS (thread-safe builds) the default; ZTS remains an opt-in build, and I can't verify events after my knowledge cutoff."}

{"answer": "yes", "explanation": "PHP 8.5 does not include generics; the generics RFCs have not been accepted, so PHP still lacks parameterized types."}

{"answer": "no", "explanation": "PHP 8.5 was released in November 2025, but I can't confirm an official PHP 8.6 release schedule or a GA date of 2026-11-19, so the claim can't be verified as true."}

{"answer": "yes", "explanation": "PHP 6 was developed but abandoned due to Unicode-related difficulties and was never released; the next major version after PHP 5.6 was PHP 7.0."}

{"answer": "yes", "explanation": "The #[\\Deprecated] attribute was added to PHP core in version 8.4 after its RFC was accepted, letting code mark functions, methods, and constants as deprecated."}

{"answer": "yes", "explanation": "In clean and onion architectures, source code dependencies point inward toward the domain at the center, so inner layers have no knowledge of outer layers."}

{"answer": "yes", "explanation": "Keeping domain entities free of framework and ORM imports (only PHP language and standard library) is a core principle of clean/hexagonal architecture."}

{"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 layers like application services and infrastructure surrounding 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": "In Clean Architecture, use cases should not depend on framework or infrastructure concerns like HTTP requests or EntityManager; they should receive plain input data and depend on abstractions."}

{"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 replaced by a new adapter without changing inner layers."}

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

{"answer": "yes", "explanation": "Value Objects are defined by their attribute values rather than a unique identity, and they are immutable, so equality is based on field values."}

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

{"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 used by developers and domain experts, derived from and reflected in the domain model."}

{"answer": "context", "explanation": "The question describes the boundary within which a model and its language stay consistent, which is the context in which the words have their intended meaning."}

{"answer": "no", "explanation": "DDD advocates a rich domain model where behavior and business rules live within entities and value objects, and the anemic model (getters/setters with logic in services) is widely considered an anti-pattern."}

{"answer": "yes", "explanation": "In Domain-Driven Design, a bounded context delimits where a particular model applies, so the same real-world concept (e.g., a Customer) can be modeled as different classes in different contexts."}

{"answer": "yes", "explanation": "The Symfony DI container instantiates a service only when it is first requested, unless it is explicitly marked as lazy-proxied or eagerly needed by another service."}

{"answer": "php bin/console debug:router", "explanation": "The debug:router command (alias for debug:route in older versions) lists all registered routes in a Symfony application."}

{"answer": "no", "explanation": "Symfony's autowiring and autoconfiguration let services be registered automatically via 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 debug mode, Symfony checks the container's tracked resource files for changes and rebuilds the cached container only when one of them has been modified, not on every request."}

{"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 must be able to call the controller action, so it has to be public; private or protected methods are not callable by the router and will fail."}

{"answer": "no", "explanation": "Event subscribers have no inherent priority over listeners; execution order is determined by the priority values assigned to each registered listener or subscriber method."}

{"answer": "yes", "explanation": "Symfony 6.0 removed the Guard authenticator system, and authentication is now handled by authenticators implementing AuthenticatorInterface."}

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

{"answer": "yes", "explanation": "Symfony voters evaluate whether a user has a given attribute (such as EDIT) on a specific subject object, and isGranted('EDIT', $post) invokes them for that purpose."}

{"answer": "yes", "explanation": "Symfony 6.0 removed support for Doctrine annotations in favour of PHP 8 attributes, so Symfony 7 validation constraints are declared with attributes such as #[Assert\\NotBlank]."}

{"answer": "yes", "explanation": "Symfony enables CSRF protection for forms by default, and the form validates the submitted CSRF token automatically (configurable via the csrf_protection option)."}

{"answer": "yes", "explanation": "Symfony's form validation constraints are enforced on the server when the form is submitted, regardless of any HTML5 client-side validation that may have passed."}

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

{"answer": "no", "explanation": "Symfony's security component does not store the plain-text password in the session; it stores the authenticated user (serialized, with the password typically hashed) and can erase credentials via eraseCredentials()."}

{"answer": "yes", "explanation": "Symfony stores bundle configuration in config/packages, typically with one YAML (or PHP/XML) file per bundle or topic, such as framework.yaml or doctrine.yaml."}

{"answer": "yes", "explanation": "This matches the Symfony convention: .env is committed with default values, and .env.local (git-ignored) holds machine-specific overrides and real secrets."}

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

{"answer": "no", "explanation": "At runtime the compiled container's ParameterBag is frozen, so calling setParameter() throws a LogicException; parameters can only be set during container building."}

{"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: true (public services were the default only in Symfony 3.4 and earlier)."}

{"answer": "no", "explanation": "Bundles work with default configuration; a config file in config/packages is optional and only needed to override defaults, since bundles can define default values in their Configuration class."}

{"answer": "yes", "explanation": "Symfony's DI container resolves environment variables in service definitions with the %env(VAR)% syntax, such as in services.yaml."}

{"answer": "APP_DEBUG", "explanation": "Symfony's APP_DEBUG environment variable toggles debug mode, which controls the profiler and Twig debugging features."}

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

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

{"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 in framework.messenger.transports."}

{"answer": "yes", "explanation": "Symfony Messenger's default transport serializer encodes messages using the JSON format via the Symfony Serializer component."}

{"answer": "yes", "explanation": "Symfony Scheduler generates messages from its schedule (RecurringMessage definitions) and dispatches them through the Messenger component's bus and transports."}

{"answer": "doctrine", "explanation": "Symfony Messenger's Doctrine transport stores messages in a database table using Doctrine DBAL, selected via the doctrine:// DSN scheme."}

{"answer": "yes", "explanation": "Symfony Messenger lets you register custom middleware in a bus's middleware list, and you can position it before or after the built-in middleware."}

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

{"answer": "8.4", "explanation": "Symfony 8.0 raises the minimum requirement to PHP 8.4, up from PHP 8.2 for Symfony 7."}

{"answer": "no", "explanation": "Symfony 7.0 removed support for docblock annotations, so routes, validation, and other config must use PHP attributes instead."}

{"answer": "yes", "explanation": "Symfony's AssetMapper component serves and versions CSS and JS without Node.js or webpack, and uses an importmap.php file to declare JavaScript dependencies."}

{"answer": "no", "explanation": "Symfony 6.4 is a long-term support (LTS) release, receiving bug fixes for 3 years and security fixes for 4 years."}

{"answer": "no", "explanation": "Symfony major releases remove features that were deprecated in the previous major branch, so code relying on those deprecated features breaks and must be updated before upgrading."}

{"answer": "yes", "explanation": "Symfony publishes an UPGRADE-x.0.md file in its repository for each major release, listing the breaking changes and migration steps."}

{"answer": "AssetMapper", "explanation": "Symfony's AssetMapper component (symfony/asset-mapper) serves and versions assets and manages importmaps without requiring Node.js or Webpack."}

{"answer": "no", "explanation": "Symfony releases every six months, so 8.0 would be around May 2026 and 8.1 around November 2026, making 8.2 expected around May 2027."}

{"answer": "no", "explanation": "Under the six-month cycle, Symfony 8.0 arrives in May 2026 and 8.1 in November 2026, so 8.2 falls in May 2027."}

{"answer": "8.2", "explanation": "Symfony minor versions ship every six months, so the release after 8.1 is 8.2, expected around November 2027."}

{"answer": "no", "explanation": "Symfony 8.2 would be a minor release, and Symfony minor versions stay backward compatible, so they don't require rewriting applications; only major versions can introduce breaking changes."}

{"answer": "no", "explanation": "PHP aims to keep minor releases backward compatible, but 8.2 added deprecations (such as dynamic properties) and some edge-case behavior changes, so code may need updates."}

{"answer": 4, "explanation": "Symfony majors end with a 4th minor that is the LTS release (like 6.4 and 7.4), so the last 8.x minor before 9.0 should be 8.4."}

{"answer": "no", "explanation": "Symfony raises its minimum PHP version only with major releases, so Symfony 8.x is expected to keep requiring PHP 8.4, not 8.5."}

{"answer": "yes", "explanation": "Symfony's backward compatibility policy only removes features deprecated in a minor release at the next major version, so 8.x deprecations stay until 9.0 at the earliest."}

{"answer": "no", "explanation": "Twig expressions inside {{ }} use Twig's own syntax and 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 HTML-escaped unless a filter like raw is applied."}

{"answer": "yes", "explanation": "Twig's `e` filter (alias of `escape`) defaults to HTML escaping, converting characters like <, >, &, and quotes into safe entities."}

{"answer": "format_number", "explanation": "The twig/intl-extra package provides the format_number filter, which formats a number according to the locale and supports options like style and currency."}

{"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 supports the `{% set %}` tag, which lets you declare and assign variables directly inside a template, not only values passed 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 components, not a single-page application framework that manages routing and application state."}

{"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 Bootstrap 4 it is built on flexbox rather than floats."}

{"answer": "yes", "explanation": "Bootstrap 5 uses the infixes sm, md, lg, xl, and xxl (xs has no infix), giving five named breakpoints."}

{"answer": "no", "explanation": "In Bootstrap, the number is an index into a spacing map (1 to $spacer*0.25, 2 to $spacer*0.5, 3 to $spacer, 4 to $spacer*1.5, 5 to $spacer*3), not a direct multiple of $spacer."}

{"answer": "data-bs-toggle", "explanation": "In Bootstrap 5, the data-bs-toggle attribute is used to activate interactive components such as dropdowns, modals, and collapses."}

{"answer": "yes", "explanation": "Bootstrap 5 dropped its jQuery dependency and its components are written in vanilla JavaScript, so they work without jQuery."}

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

{"answer": "no", "explanation": "Doctrine ORM does not create tables at runtime; schema changes are made explicitly via commands such as doctrine:schema:update or migrations."}

The Doctrine ORM method is persist(), which marks an entity for insertion and makes it managed; the actual SQL INSERT runs on flush(). ⏎  ⏎ {"answer": "persist", "explanation": "EntityManager::persist() schedules a new entity for insertion and makes it managed, with no SQL executed until flush() is called."}

{"answer": "no", "explanation": "Doctrine ORM 3.0 removed EntityManager::merge(), which was deprecated in 2.x; the method no longer exists."}

{"answer": "yes", "explanation": "DQL (Doctrine Query Language) queries reference 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 does not flush automatically at the end of a request; changes must be persisted explicitly by calling EntityManager::flush()."}

{"answer": "yes", "explanation": "Doctrine's Unit of Work tracks managed entities, so flush() detects property changes and issues the UPDATE without calling persist()."}

{"answer": "no", "explanation": "In Doctrine's EntityManager, remove() only schedules the entity for deletion; the SQL DELETE is executed 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 consistent snapshot while writers create new row versions."}

{"answer": "EXPLAIN", "explanation": "EXPLAIN displays the query execution plan the optimizer would use without actually running the statement."}

{"answer": "no", "explanation": "SERIAL creates a sequence with a column DEFAULT of nextval(), while GENERATED AS IDENTITY is the SQL-standard mechanism that rejects explicit inserts unless OVERRIDING is used, so they differ in behavior."}

{"answer": "no", "explanation": "In PostgreSQL, NULL values are considered distinct from each other, so a UNIQUE constraint allows multiple rows with NULL in the column by default (unless NULLS NOT DISTINCT is specified in PostgreSQL 15+)."}

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

{"answer": "no", "explanation": "Plain VACUUM only marks dead tuple space as reusable within the table and does not shrink the file or return space to the operating system; VACUUM FULL is needed for that."}

{"answer": "PARTITION BY", "explanation": "The PARTITION BY clause divides the result set into groups over which the window function is computed independently."}

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

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

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

{"answer": "yes", "explanation": "UPDATE and DELETE statements with WHERE clauses on indexed columns can locate matching rows faster via the index, just like SELECT."}

{"answer": "yes", "explanation": "ROLLBACK TO SAVEPOINT undoes only the statements executed after the named savepoint while keeping the rest of the transaction open."}

{"answer": "no", "explanation": "EXPLAIN ANALYZE actually executes the query and reports real timing and row counts, whereas plain EXPLAIN only shows the plan without executing 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 includes only the 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 conflict rather than locking the rows read."}

{"answer": "yes", "explanation": "HTTP status 201 Created indicates that 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 to return in the response body."}

{"answer": "yes", "explanation": "RFC 9110 defines DELETE as idempotent, meaning repeated identical requests have the same intended effect on server state, though the response status may differ (e.g., 200 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 instead."}

{"answer": "yes", "explanation": "HTTP status 429 Too Many Requests indicates the user has sent too many requests in a given time, 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 password_verify() instead."}

{"answer": "yes", "explanation": "A session-bound CSRF token generated by the server and checked 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; an access token grants delegated access to resources and does not itself identify the user (OpenID Connect adds the ID token for authentication)."}

{"answer": "no", "explanation": "XSS is prevented by context-aware output encoding/escaping when data is rendered, since input validation alone cannot stop all XSS and data may be safe in one context but not another."}

{"answer": "code", "explanation": "The authorization server redirects to redirect_uri with a 'code' query parameter, which the client 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 prevent precomputed rainbow table attacks, and verification uses the stored salt."}

{"answer": "no", "explanation": "PHPUnit only discovers and runs test classes that extend PHPUnit\\Framework\\TestCase (or otherwise implement its Test interface), so extending it is required."}

{"answer": "no", "explanation": "PHPUnit's setUp() runs before each individual test method, not once before the whole 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 expects an exception of the given class to be thrown."}

{"answer": "no", "explanation": "It is reversed: a stub only returns canned data for method calls, while a mock additionally verifies that expected methods were called on it."}

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

{"answer": "no", "explanation": "PHPUnit supports test dependencies through the @depends annotation (or #[Depends] attribute), which lets one test consume the return value of another."}

{"answer": "--order-by=random", "explanation": "PHPUnit's --order-by option with the random value runs tests in random order (also settable via --random-order, which exists in newer versions as a shortcut)."}

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

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

{"answer": "true", "explanation": "Both '1e1' and '10' are numeric strings, so PHP compares them numerically (10 == 10), which is 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 matched 'zero')."}

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

{"answer": "[hello]", "explanation": "A negative start larger than the string length is clamped to 0, so substr returns the whole string 'hello'."}

{"answer": "k,n,m", "explanation": "The + operator merges arrays, keeping the left array's keys first (k, n) and then adding keys only present on the right (m), so array_keys yields k, n, m."}

{"answer": "yxz", "explanation": "Sorting by index 2 ascending puts [2,'y',1] first, and since PHP 8's sort is stable the tied elements keep their order, giving y, x, z."}

{"answer": 4, "explanation": "Since PHP 8.1, spreading an array with string keys passes them as named arguments, so a=5 and b=1, giving 5 - 1 = 4."}

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

{"answer": "B", "explanation": "static::class resolves to the late static binding class, which is B since the method is called on a B instance."}

{"answer": 10, "explanation": "Inside its own set hook, assigning to $this->x bypasses the hook (recursion guard), so the backing value is set to 5 * 2 = 10, which is then echoed."}

{"answer": "BA", "explanation": "The `insteadof` rule makes TC's `f` come from TB (returns 'B'), and the `TA::f as g` alias makes `g` the TA version (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 get their own $n, and setting CX::$n 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 the function returns 2."}

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

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

{"answer": "noyes", "explanation": "class_exists('Foo') looks for a global class and returns false, while class_exists('Ns\\Foo') finds the namespaced class and returns true."}

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

{"answer": 3, "explanation": "Since PHP 8.1, an inherited method that isn't overridden shares its static variables with the parent, so $n is incremented to 1, then 2, then 3 across the three calls."}

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

{"answer": "ok,2", "explanation": "iterator_to_array preserves keys: inner yields keys 0 and 1 (1, 2), then outer's own yield gets key 0 and overwrites the value 1 with 'ok', leaving [0=>'ok', 1=>2]."}

{"answer": "noyes", "explanation": "The hash was made with cost 4, so checking against cost 4 returns 'no', while checking against cost 5 returns 'yes' because the cost differs."}

{"answer": "strict-in", "explanation": "Since PHP 8.0, E_ALL is 32767, which includes the E_STRICT bit (2048), so E_ALL & 2048 is 2048, not 0."}

{"answer": "mapped", "explanation": "Request::create passes the server array into the constructor, and ServerBag::getHeaders() converts HTTP_X_TOKEN into the header X-Token, so the lookup returns 'abc'."}

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

{"answer": "same", "explanation": "Doctrine's identity map returns the already-managed entity instance for both find() calls, so $a and $b are the same object."}

{"answer": 0, "explanation": "Removing an entity that was persisted but not yet flushed cancels its scheduled insert, so nothing is written and the table stays empty."}

{"answer": 1, "explanation": "count(column) counts only non-NULL values, and the table holds 1 and NULL, so only the 1 is counted."}

{"answer": "10,30,60", "explanation": "The window sum is a running total ordered by id (10, 30, 60), and string_agg concatenates these in id order with commas."}

{"answer": "M1M2", "explanation": "The bus runs the first middleware, which echoes M1 and then passes to the next, which echoes M2; the end of the stack returns the envelope without output."}

{"answer": 11, "explanation": "HandleMessageMiddleware invokes every handler registered for Ping (neither has been handled yet), so $n becomes 1 + 10 = 11."}

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

{"answer": 2, "explanation": "The UNIQUE constraint is deferred until commit, so both inserted rows are visible within the open transaction and the count is 2 (the violation would only surface at COMMIT)."}

{"answer": 6, "explanation": "The filter `test_sum` matches both `test_sum` and `test_sum_abs`, each with 3 data sets, while `test_other` is excluded, giving 3 + 3 = 6."}

{"answer": "2, 1", "explanation": "The data provider yields two cases: x=1 passes the assertion, and x=-1 fails it, so two tests run and one fails."}

{"answer": "POST", "explanation": "Using -d (--data) with curl makes it send a POST request by default, unless another method is specified with -X."}

{"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 client authentication failures, including an unknown client."}

{"answer": "fragment", "explanation": "With response_type=token (implicit grant), the authorization server returns the access_token in the URL fragment (after #) of the redirect_uri."}

{"answer": 6, "explanation": "The default filter returns 2 because false counts as empty, and the filter binds tighter than *, so 2 * 3 = 6."}

{"answer": "TypeError", "explanation": "Twig's `~` binds tighter than `+`, so this parses as ('a' ~ 1) + 2, which adds the non-numeric string 'a1' to 2 and PHP 8 throws a TypeError."}

{"answer": 0, "explanation": "The value is the array [''], which is not null or an empty string, so NotBlank passes and there are no violations."}

{"answer": "invalid", "explanation": "The form is never submitted, and Symfony's isValid() returns false for unsubmitted forms instead of throwing, so the ternary outputs 'invalid'."}

{"answer": "same", "explanation": "Services registered with the default shared behavior return the same instance on each get() call, so the object IDs match."}

{"answer": "hi Bob!", "explanation": "Symfony resolves parameter placeholders recursively at compile time, so %greeting% expands to 'hi %name%', which then expands to 'hi Bob', giving 'hi Bob!'."}

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

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

{"answer": 2, "explanation": "The Domain layer depends on both Application (PlaceOrder) and Infrastructure (Db) through the promoted constructor property types, and Domain may only depend on Domain, so each is one violation."}

{"answer": 3, "explanation": "Domain may only depend on Domain, so the three cross-layer references (PlaceOrder from Application, Db and the fully qualified Logger from Infrastructure) each count as a violation."}

{"answer": "10,15", "explanation": "The add method returns a new Money instance without modifying $a, so $a->amount stays 10 and $c->amount is 15."}

{"answer": 1, "explanation": "After adding 'a', remove('a') sees count 1 and throws DomainException, which is caught without removing the item, so count() still returns 1."}

{"answer": "hi", "explanation": "Since PHP 8.4, a method can be called directly on a `new` expression with `new C()->hi()`, so it returns 'hi' and echo prints it."}

{"answer": "yesno", "explanation": "The ghost starts uninitialized, so the first check prints 'yes'; reading $o->v runs the initializer, which sets v, 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 on 8.1."}

{"answer": "noyes", "explanation": "AnnotationClassLoader was deprecated in 6.4 and removed in Symfony 7.0, while its replacement AttributeClassLoader still exists in 8.1, so class_exists returns false then true."}