Карта знаний PHP — qwen3.8:latest, run-07 · think: off

{"answer": "no", "explanation": "Single-quoted strings are not interpreted for variables or escapes, while double-quoted strings are."}

{"answer": "yes", "explanation": "The null coalescing operator (??) suppresses 'undefined variable' notices and evaluates the left operand using isset() semantics."}

{"answer": "ab", "explanation": "The comma operator concatenates the two strings 'a' and 'b' into a single output of 'ab'."}

{"answer": "no", "explanation": "In PHP, `print` is a language construct, not a function; it does not return a value (it returns void) and thus cannot be used inside an expression like `echo` can (though `echo` also cannot be used in expressions, `print` specifically returns nothing, whereas functions return values)."}

{"answer": "no", "explanation": "The Elvis operator returns the right operand when the left operand is falsy."}

{ ⏎   "answer": "yes", ⏎   "explanation": "In PHP, the string concatenation operator (.) has a higher precedence than addition and subtraction, meaning expressions like $a . $b + $c are evaluated as ($a . $b) + $c, not $a . ($b + $c)." ⏎ }

{"answer": "no", "explanation": "In PHP, the exponentiation operator ** is right-associative, so 2 ** 3 ** 2 is evaluated as 2 ** (3 ** 2) = 2 ** 9 = 512, not (2 ** 3) ** 2 = 64."}

{"answer": "sum: 5", "explanation": "In PHP, the concatenation operator '.' has higher precedence than the addition operator '+', so the expression is evaluated as (echo ('sum: ' . 2)) + 3. 'sum: ' . 2 results in the string 'sum: 2'. Then, 'sum: 2' + 3 is evaluated. Since 'sum: 2' is not a numeric string (it starts with letters), it is cast to 0 in the addition context. Thus, 0 + 3 equals 3. However, the question asks what string it *prints*. The echo statement outputs the result of the expression before the addition? No, wait. The entire expression is the argument to echo? No, `echo` is a statement, not a function. The expression is `'sum: ' . 2 + 3`. Precedence rules: `.` is higher than `+`. So it is `('sum: ' . 2) + 3`. `'sum: ' . 2` is `'sum: 2'`. `'sum: 2' + 3` casts `'sum: 2'` to integer 0, so 0 + 3 = 3. The result of the expression is the integer 3. `echo 3` prints `3`. Wait, let me re-read carefully. The code is `echo 'sum: ' . 2 + 3;`. Is `echo` part of the expression precedence? No. The expression being echoed is `'sum: ' . 2 + 3`. Due to precedence, it is `('sum: ' . 2) + 3`. `'sum: 2'` is cast to 0. `0 + 3` is `3`. `echo 3` prints `3`. Let me double check if I misinterpreted the precedence. Yes, concatenation is higher. So the string 'sum: 2' is created, then added to 3. Since it's not a numeric string, it becomes 0. Result is 3. Print is 3."}

{"answer": "no", "explanation": "With strict comparison (===), arrays are considered equal only if they have the same key/value pairs in the same order and are of the same type."}

```json ⏎ {"answer": "no", "explanation": "0 == false actually returns true, as PHP's loose comparison considers 0 and false equal (they both evaluate to falsy)."} ⏎ ```

```json ⏎ {"answer": "yes", "explanation": "In PHP 8, a non-numeric string like \"abc\" is compared to the integer 0 by checking if the string is an empty string or if it evaluates to zero numerically, and since \"abc\" does not start with a digit, it is considered equivalent to 0 in a loose comparison."} ⏎ ```

```json ⏎ {"answer": "yes", "explanation": "In PHP, under loose comparison (==), null is considered equal to 0, the empty string, and false."} ⏎ ```

{"answer": 42, "explanation": "In PHP, casting a string starting with a number to int returns the leading numeric portion, ignoring the rest."}

{"answer": 10, "explanation": "In PHP, when a string representing a number is used in an arithmetic operation with an integer, the string is cast to an integer, so '5' becomes 5, and 5 + 5 equals 10."}

{"answer": "yes", "explanation": "In PHP, casting the boolean value false to a string results in the string \"0\"."}

{ ⏎   "answer": "yes", ⏎   "explanation": "Floating-point arithmetic results in 0.30000000000000004 for 0.1 + 0.2, so the strict comparison to 0.3 is false." ⏎ }

```json ⏎ {"answer": "no", "explanation": "strrev() operates byte-by-byte and does not correctly handle multi-byte UTF-8 characters, corrupting them."} ⏎ ```

{"answer": "yes", "explanation": "str_checks if the haystack contains the needle, and 'world' is present in 'Hello world'."}

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

{"answer": "yes", "explanation": "The default charlist for trim() is ' \\t\\n\\r\\0\\x0B', which includes tabs, newlines, carriage returns, null bytes, and vertical tabs, not just spaces."}

{"answer": 6, "explanation": "The string 'héllo' contains the character 'é' which is encoded as 2 bytes in UTF-8, plus 4 other single-byte characters, totaling 6 bytes."}

{"answer": "def", "explanation": "In PHP, a negative start position in substr() counts from the end of the string, so -3 returns the last three characters."}

{"answer": "no", "explanation": "In PHP, strings are passed by value to functions, so functions like ucfirst() return a new string without modifying the original variable."}

{"answer": "yes", "explanation": "Heredoc strings allow variable interpolation and escape sequence processing, whereas nowdoc strings are treated as literal raw strings without interpolation."}

```json ⏎ {"answer": "no", "explanation": "The sort() function re-indexes numeric keys sequentially, so it does not preserve the original key-to-value associations."} ⏎ ```

{"answer": "yes", "explanation": "In PHP, numeric string keys like '5' are automatically cast to integers and stored as integer keys in arrays."}

{"answer": "no", "explanation": "The third parameter of in_array(), which enables strict comparison, defaults to false."}

{"answer": "yes", "explanation": "By default, array_filter() removes elements that evaluate to false (including 0, null, false, empty string, and 0.0)."}

{"answer": "no", "explanation": "By default, array_slice() re-indexes the resulting array unless the preserve_keys parameter is explicitly set to true."}

{"answer": [20, 30], "explanation": "array_slice extracts elements starting at index 1 (value 20) with a length of 2, returning an array of the next two elements."}

{"answer": 2, "explanation": "Array union keeps the left-hand array's values for duplicate keys, so 'a' remains 1 and 'b' is added, resulting in two elements."}

{"answer": "yes", "explanation": "In PHP 8.1, the array spread operator was extended to support string keys, allowing arrays with string keys to be merged using [...$a, ...$b]."}

{"answer": "yes", "explanation": "PHP prohibits mixing named arguments and the argument unpacking operator (...$args) within the same function call."}

{"answer": "no", "explanation": "In PHP, closures (anonymous functions) must explicitly use the 'use' keyword to import variables from the outer scope; they do not automatically have access to them by default."}

```json ⏎ { ⏎   "answer": 3, ⏎   "explanation": "func_num_args() returns the number of arguments passed to the function, which is 3 for the call f(1, 2, 3)." ⏎ } ⏎ ```

```json ⏎ {"answer": "yes", "explanation": "In PHP, the body of an arrow function (fn) can consist of multiple expressions within curly braces, though typically it's a single expression without braces."} ⏎ ```

{"answer": "no", "explanation": "Arrow functions in PHP capture outer variables by value at the time of creation, not by reference."}

{"answer": "yes", "explanation": "In PHP, static closures do not have access to the $this variable, meaning they cannot capture or use the context of the instance from which they are created."}

{"answer": "5", "explanation": "The closure captures the value of $x by value at the time of definition, so it returns 5 regardless of the later reassignment to 7."}

```json ⏎ { ⏎   "answer": "yes", ⏎   "explanation": "In weak typing mode, PHP permits implicit type coercion, so a numeric string like \"5\" is automatically converted to the integer 5 when passed to an int parameter." ⏎ } ⏎ ```

{"answer": "yes", "explanation": "PHP 8.0 introduced constructor property promotion, allowing properties to be declared directly in the constructor parameter list."}

{"answer": "final", "explanation": "In PHP, declaring a method as 'final' prevents it from being overridden by any subclass."}

```json ⏎ {"answer": "yes", "explanation": "In PHP, a method marked as final cannot be overridden in any subclass."} ⏎ ```

{"answer": "no", "explanation": "Private properties in a parent class are not accessible in a subclass."}

{"answer": "class@anonymous", "explanation": "Anonymous classes in PHP 7+ have a generated name starting with 'class@anonymous', followed by a NUL byte and location details."}

{"answer": "yes", "explanation": "In PHP, private methods are not inherited or visible to child classes, so a child class can declare a method with the same name and any visibility without violating inheritance rules."}

{ ⏎  "answer": "no", ⏎  "explanation": "The __get() magic method is triggered only when accessing inaccessible (private or protected) properties from outside the class, not strictly non-existent ones; however, it is often used to simulate properties that are not directly accessible, but technically it applies to inaccessible ones, not just non-existent. Actually, the precise rule is: __get is called when reading inaccessible (private/protected) properties. If a property is public, __get is not called. If a property is not defined at all and there is no property access, __get is not called (unless using late static binding or similar, but generally it's for inaccessible). Wait, if a property is not defined and you access it, it triggers a notice and returns null, it does NOT call __get. __get is ONLY for inaccessible (private/protected) properties. So the statement \"called only for non-existent properties\" is false because it's called for inaccessible properties, which may exist but are just inaccessible. Also, it is NOT called for truly non-existent public properties. So the answer is false." ⏎ }

{"answer": "Error", "explanation": "Attempting to write to a readonly property in PHP throws a TypeError, which is a subclass of \\Error, not \\Exception."}

{"answer": "yes", "explanation": "In PHP, interfaces can declare class constants, but they cannot declare properties or methods (other than abstract ones)."}

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

{"answer": "yes", "explanation": "PHP interfaces can declare static methods, which can be called using the :: operator without instantiating the interface, though implementations are not required for the interface contract."}

{"answer": "no", "explanation": "The instanceof operator checks both class inheritance and interface implementation."}

{"answer": "no", "explanation": "Interface methods must be abstract and cannot have implementations; only traits (and classes) can provide concrete method bodies."}

```json ⏎ {"answer": "yes", "explanation": "Abstract methods in PHP can have public, protected, or private visibility, though protected is commonly used in abstract classes for internal use."} ⏎ ```

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

{"answer": "yes", "explanation": "Traits in PHP can declare constants, which are inherited by any class that uses the trait."}

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

{ ⏎   "answer": "no", ⏎   "explanation": "In PHP 8, TypeError inherits from the Throwable interface, not from Exception; specifically, it extends Error, so a catch block for Exception will not catch it." ⏎ }

{"answer": "no", "explanation": "The @ operator suppresses warnings and notices, but exceptions are still thrown and must be caught with try-catch blocks."}

{"answer": "DivisionByZeroError", "explanation": "intdiv(5, 0) throws a DivisionByZeroError, which is a subclass of ArithmeticError."}

{"answer": "no", "explanation": "The finally block always executes, regardless of whether an exception was thrown or caught."}

{ ⏎  "answer": "no", ⏎  "explanation": "If an exception is thrown inside a finally block, it will immediately terminate the execution and the previous exception from the try-catch block is suppressed (unless using Throwable and specific chaining mechanisms, but generally the finally exception replaces the flow)." ⏎ }

{"answer": "yes", "explanation": "In PHP, casting a non-null object to boolean results in true."}

{"answer": "no", "explanation": "Functions registered via register_shutdown_function() run when the script execution finishes, which includes a normal end, fatal error, or an exit/die call, but the statement says they run 'when exit is called' which is partially true but misleading because they also run on other conditions; however, strictly speaking, exit does trigger them, but the phrasing 'run when exit is called' might be interpreted as exclusively, but in PHP, exit does trigger shutdown functions. Wait, let me re-evaluate: Actually, exit DOES trigger shutdown functions. So the statement is essentially true. But the question is tricky. Let me check PHP docs: 'These functions are called when the script execution ends, either by reaching the end of the script, a fatal error, or an exit/die statement.' So exit does trigger them. So answer should be yes. But wait, the question says 'Functions registered via register_shutdown_function() run when exit is called.' That is a true statement. So answer is yes."}

{"answer": "no", "explanation": "The 'use' statement only creates an alias for the class name; the class file is actually loaded when the class is first instantiated or referenced, provided an autoloader is configured."}

```json ⏎ { ⏎   "answer": "function", ⏎   "explanation": "To import a function in PHP, you use the 'function' keyword with the 'use' statement, while classes use their name directly." ⏎ } ⏎ ```

{"answer": "Controller/Api/UserController.php", "explanation": "The PSR-4 rule maps the namespace App\Controller\Api to the directory Controller/Api under the src/ prefix, and the class name UserController corresponds to the file UserController.php."}

{"answer": "yes", "explanation": "Composer's vendor/autoload.php registers the Composer autoload class, which in turn calls spl_autoload_register to handle class loading."}

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

{ ⏎   "answer": "no", ⏎   "explanation": "Unqualified class names in `new` expressions are resolved relative to the current namespace, not the global root (unless the namespace is global)." ⏎ }

{"answer": "yes", "explanation": "PSR-4 maps the namespace prefix 'App\\' to the base directory 'src/', so the remaining namespace path 'Model\\User' corresponds to the file path 'Model/User.php' relative to that base directory."}

{"answer": "yes", "explanation": "In PHP, use statements inside a function body scope the alias to that function only."}

```json ⏎ {"answer": "yes", "explanation": "In PHP, arrays are copied on assignment by default, meaning modifying one array does not affect the other unless a reference is explicitly used."} ⏎ ```

{"answer": 2, "explanation": "PHP arrays are copied by value (Copy-on-Write), so modifying $b does not affect $a."}

{"answer": "yes", "explanation": "In PHP, variables declared outside functions are in global scope and cannot be accessed directly inside a function without using the 'global' keyword, the '$GLOBALS' superglobal array, or passing them as arguments."}

{"answer": "no", "explanation": "The $GLOBALS array is a reference to the global symbol table, so unsetting a key in it removes the variable from the global scope entirely, not just locally."}

{"answer": "6", "explanation": "The function increments the variable passed by reference, so $n becomes 6."}

{"answer": "no", "explanation": "PHP iterates over a snapshot of the array's elements at the start of the loop when iterating by value, so changes made to the array within the loop do not affect the current iteration."}

{"answer": "no", "explanation": "Static properties belong to the class, not to individual instances, so changes are shared across all instances."}

{"answer": "no", "explanation": "In PHP, array keys of type boolean are cast to integers (true becomes 1, false becomes 0) and stored as integers, not booleans."}

{"answer": "yes", "explanation": "Since PHP 7.0, generators support return values that can be retrieved using the getReturn() method after the generator is complete."}

{"answer": "no", "explanation": "Generators in PHP are single-use iterators; once they are fully consumed (or closed), their internal state is destroyed and they cannot be rewound or reused. To iterate again, you must create a new generator instance."}

{ ⏎   "answer": "yes", ⏎   "explanation": "The `yield from` expression in Python delegates the iteration to another iterable, effectively flattening the generator structure." ⏎ }

{"answer": "Generator", "explanation": "In PHP, yielding from a function returns a Generator object, so get_class(g()) returns the class name \"Generator\"."}

{"answer": 3, "explanation": "The generator yields three values (1, 2, 3), so iterator_to_array returns an array with 3 elements."}

{"answer": "no", "explanation": "SplStack implements a Last-In-First-Out (LIFO) queue, not FIFO."}

{"answer": "yes", "explanation": "ArrayIterator is a built-in PHP class that implements the Iterator interface, allowing arrays to be traversed using foreach or iterator methods."}

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

{ ⏎   "answer": "yes", ⏎   "explanation": "The password_hash() function in PHP automatically generates a secure, random salt internally and prefixes it to the resulting hash string." ⏎ }

{"answer": "no", "explanation": "In PHP 8, PASSWORD_DEFAULT is bcrypt, not md5."}

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

{"answer": "no", "explanation": "strip_tags() removes HTML tags to prevent XSS, but SQL injection is prevented by using prepared statements and parameterized queries."}

```json ⏎ {"answer": "yes", "explanation": "session_regenerate_id() creates a new session ID, which prevents attackers from hijacking sessions by guessing or stealing previous session IDs."} ⏎ ```

{"answer": "php_sapi_name", "explanation": "The built-in function php_sapi_name() returns the name of the current SAPI interface, such as 'cli' or 'apache2handler'."}

{ ⏎ "answer": "yes", ⏎ "explanation": "session_destroy() only removes the session data from the server; it does not delete the PHPSESSID cookie on the client side, which requires explicit cookie deletion (e.g., using setcookie with a past expiry date) or manual removal by the user." ⏎ }

{"answer": "no", "explanation": "The $_SESSION array is only populated after session_start() is called to initialize the session."}

{"answer": "8.3", "explanation": "The array_find() function was added in PHP 8.3."}

{"answer": "yes", "explanation": "PHP 8.4 introduced property hooks (getters, setters, and initializers) as a new feature."}

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

{"answer": "8.4", "explanation": "The #[\\NoDiscard] attribute was introduced in PHP 8.4 to indicate that the return value of a function must not be ignored."}

```json ⏎ {"answer": "8.4", "explanation": "PHP 8.4 introduced the pipe operator |> for chaining function calls in a more readable way."} ⏎ ```

{"answer": "8.4", "explanation": "Clone with arguments (allowing custom properties during cloning) was introduced in PHP 8.4."}

{"answer": 8.4, "explanation": "The array_first() and array_last() functions were introduced in PHP 8.4 to provide built-in ways to retrieve the first and last elements of an array."}

{"answer": 8.3, "explanation": "The RFC Partial Function Application v2 was adopted for PHP 8.3."}

{ ⏎ "answer": "8.4", ⏎ "explanation": "The clamp() function was introduced in PHP 8.4 via the RFC for improved clamping functionality." ⏎ }

{"answer": "no", "explanation": "Context managers (or resource management via a specific RFC distinct from try/finally) have not been adopted in PHP as of 2026; the standard error handling mechanism remains try/catch/finally."}

{"answer": "yes", "explanation": "The RFC for Bound-Erased Generic Types was voted down and declined by the PHP core team."}

```json ⏎ { ⏎   "answer": "no", ⏎   "explanation": "As of November 7, 2026, PHP has not accepted an RFC to enable multithreading (ZTS) by default; this remains a topic of discussion in the PHP community." ⏎ } ⏎ ```

{"answer": "yes", "explanation": "PHP does not support true generics (parameterized types) like Java or C#; even as of recent versions, type hints are invariant and do not provide compile-time generic type checking."}

{"answer": "no", "explanation": "PHP 8.5 was not the latest stable version on that date; PHP 8.4 is the latest stable, and PHP 8.5 was not yet released or stable."}

{"answer": "no", "explanation": "PHP 6 was a planned development branch that was abandoned, and the versioning skipped directly from PHP 5.6 to PHP 7.0."}

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

```json ⏎ {"answer": "yes", "explanation": "In clean and onion architectures, the dependency rule ensures that high-level policies (inner layers) do not depend on low-level details (outer layers), and all dependencies point toward the center."} ⏎ ```

{"answer": "yes", "explanation": "In a clean architecture or DDD approach, domain entities must be pure PHP classes independent of any framework or ORM to ensure testability and separation of concerns."}

{"answer": "no", "explanation": "Controllers and Twig templates belong to the presentation layer, not the business-logic layer."}

{"answer": "Domain Core", "explanation": "In Onion Architecture, the Domain Core (or domain model) is the innermost layer containing the essential business logic, with all other layers depending on it inward."}

{"answer": "yes", "explanation": "Tools like DePTRAC allow defining layer dependency rules and will fail the build if code violates these architectural constraints."}

{"answer": "no", "explanation": "Use cases (or interactors) should not depend on framework-specific details like HTTP requests; they should be decoupled from the presentation layer to ensure testability and reusability."}

{"answer": "Repository", "explanation": "The Repository pattern acts as an in-memory collection of domain objects, abstracting the persistence mechanism."}

```json ⏎ {"answer": "yes", "explanation": "In clean architecture, data access details are isolated in the outer infrastructure layer, allowing the core domain and use cases to remain independent of the specific database used."} ⏎ ```

```json ⏎ { ⏎   "answer": "no", ⏎   "explanation": "In DDD, an aggregate is a cluster of domain objects treated as a single unit, not necessarily mapped to a single database table." ⏎ } ⏎ ```

{ ⏎   "answer": "yes", ⏎   "explanation": "In Domain-Driven Design, a Value Object is defined by its immutable attributes and equality is determined by the values of those attributes rather than object identity." ⏎ }

{ ⏎ "answer": "Root", ⏎ "explanation": "In Domain-Driven Design, the Root of an Aggregate is the single entry point that guarantees consistency and encapsulation for all changes within the aggregate." ⏎ }

{"answer": "yes", "explanation": "In Domain-Driven Design, repositories are defined for aggregate roots to ensure that all entities within the aggregate are accessed and modified as a single consistent unit, preventing inconsistent state across individual entities."}

{"answer": "yes", "explanation": "Ubiquitous Language is a core Domain-Driven Design concept where the domain model terms are shared and consistent among developers, domain experts, and all documentation."}

{"answer": "semantics", "explanation": "In computer science and linguistics, the specific meaning or interpretation of a language within a defined context or model is referred to as its semantics."}

{ ⏎   "answer": "no", ⏎   "explanation": "DDD encourages rich domain models where behavior and logic reside in domain objects, not just data containers with logic in services." ⏎ }

{ ⏎ "answer": "yes", ⏎ "explanation": "In Domain-Driven Design, a bounded context defines the boundary where a specific model applies, allowing the same business concept to have different meanings and implementations (classes) in different contexts." ⏎ }

```json ⏎ {"answer": "yes", "explanation": "In Symfony's DI container, services are instantiated lazily, meaning they are created only when first requested."} ⏎ ```

{"answer": "debug:router", "explanation": "The `debug:router` command in Symfony is used to list all registered routes."}

{ ⏎ "answer": "no", ⏎ "explanation": "The core purpose of autowiring is to automatically resolve dependencies by type-hinting, eliminating the need to manually declare most services." ⏎ }

{ ⏎   "answer": "yes", ⏎   "explanation": "Twig's template cache converts compiled PHP code into class files to improve performance, preventing recompilation on every request." ⏎ }

{"answer": "no", "explanation": "In the Symfony dev environment, the Dependency Injection container is typically dumped/rebuilt on every request (or when the cache is cleared) to ensure the latest configuration changes are reflected, unless specific performance optimizations like OpCache are masking the file writes, but the standard behavior is not 'only after tracked files change' in the way implied by the prompt's contrast with production; actually, the dev environment checks if the container cache is stale based on configuration files, so it does NOT rebuild on every request, it rebuilds when config files change. Wait, let me re-read the standard Symfony behavior. In dev, the container is dumped to cache. On subsequent requests, Symfony checks if the cache is valid. If the configuration files (services.yaml, etc.) have not changed, the cache is used. If they have changed, it is rebuilt. So the statement 'rebuilt only after tracked files change, not on every request' is actually TRUE for the dev environment. Let me double check. Yes, Symfony dev environment caches the compiled container. It only recompiles when the container config files (tracked files) are modified. It does NOT recompile on every single request. Therefore the statement is True."}

{"answer": "APP_ENV", "explanation": "The APP_ENV environment variable is used by the Symfony runtime to determine the active environment, such as dev, test, or prod."}

{"answer": "no", "explanation": "Symfony controller methods must be public because the framework invokes them via reflection or direct calls from the outside, and private/protected methods are not accessible."}

{"answer": "no", "explanation": "Listeners are dispatched first to allow for short-circuiting or modification before the heavier subscriber logic runs."}

```json ⏎ {"answer": "yes", "explanation": "In Symfony 5.3 and later, the modern firewall-based authentication system using AuthenticatorInterface was introduced, and the older Guard system was deprecated and eventually removed."} ⏎ ```

{"answer": "IsGranted", "explanation": "The #[IsGranted] attribute in Symfony Security checks user roles or permissions and throws an AccessDeniedException (403) if the check fails."}

{"answer": "yes", "explanation": "Symfony Security uses Voters to determine permissions for specific subjects/objects via the isGranted method."}

{"answer": "yes", "explanation": "Symfony 5.3+ deprecates annotations and 6.0+ removes them, making PHP attributes the standard for validation and other metadata in Symfony 7+."}

{ ⏎   "answer": "yes", ⏎   "explanation": "Symfony forms include CSRF protection by default, automatically adding and validating a CSRF token unless explicitly disabled." ⏎ }

```json ⏎ {"answer": "yes", "explanation": "Symfony's form validation framework handles both client-side (via JavaScript) and server-side validation, ensuring that data is validated on the server regardless of client-side checks."} ⏎ ```

```json ⏎ {"answer": "make:form", "explanation": "The Symfony command 'make:form' generates a form class (FormType) for a specified entity or standalone."} ⏎ ```

{"answer": "no", "explanation": "Symfony never stores user passwords in plain text, using BCrypt or similar hashing algorithms instead."}

{ ⏎ "answer": "yes", ⏎ "explanation": "Symfony follows a convention where bundle-specific configuration is stored in separate files within the config/packages directory, organized by bundle or topic (e.g., config/packages/doctrine.yaml)." ⏎ }

{"answer": "yes", "explanation": "This is a common security best practice in modern PHP frameworks (like Laravel and Symfony) where .env defines safe defaults and .env.local holds sensitive credentials excluded from version control."}

{"answer": "container:debug", "explanation": "The Symfony CLI command `container:debug` is used to list the container's registered services and their aliases."}

{ ⏎ "answer": "yes", ⏎ "explanation": "The Symfony DI container allows setting new parameters at runtime using setParameter(), although this is not recommended for critical business logic." ⏎ }

{"answer": "no", "explanation": "By default, Symfony services are private to improve performance and memory usage; they must be explicitly marked as public to be fetched directly from the container."}

{"answer": "no", "explanation": "Bundles can function with default configurations defined in code (like DependencyInjection extensions) without requiring a dedicated YAML/XML config file in the config/packages directory."}

{"answer": "yes", "explanation": "In Symfony, the %env(VAR)% syntax is used in YAML configuration files to reference environment variables."}

{"answer": "APP_DEBUG", "explanation": "In Symfony, the APP_DEBUG environment variable controls debug mode, enabling the profiler and Twig debugging features."}

{"answer": "no", "explanation": "In Symfony Messenger, a single message can be handled by multiple handlers if they are defined for the same bus and message type, and there is no strict restriction to only one handler per message by default (though priority and stopping propagation can affect which run)."}

```json ⏎ {"answer": "no", "explanation": "The sync transport in Messenger processes the message immediately and synchronously, rather than queuing it for a worker like async does."} ⏎ ```

{"answer": "php bin/console messenger:consume", "explanation": "The command 'php bin/console messenger:consume' starts the worker that processes messages from the Symfony Messenger component's queues."}

{"answer": "no", "explanation": "In Symfony Messenger, the retry strategy (number of retries and delay) is configured in the 'framework' > 'messenger' > 'routing' configuration per message, not per transport."}

{"answer": "yes", "explanation": "Symfony Messenger defaults to the json serializer if no specific serializer is configured in the messenger.transport configuration."}

{"answer": "yes", "explanation": "The Symfony Scheduler component allows defining tasks that generate messages which are then dispatched to the Symfony Messenger component for processing."}

{"answer": "doctrine", "explanation": "The 'doctrine://' transport in Symfony Messenger uses Doctrine to persist messages into database tables."}

{"answer": "no", "explanation": "Laravel's pipeline mechanism requires middleware to be passed as an ordered array at runtime; it does not support a static, built-in list of middleware that can be dynamically extended with custom ones before or after them."}

{"answer": "yes", "explanation": "Symfony follows a release cycle of major versions every two years (typically November) and new LTS or non-LTS minor releases every six months (May and November)."}

{"answer": "8.2", "explanation": "Symfony 8 requires PHP 8.2 or later as its minimum version."}

{ ⏎   "answer": "no", ⏎   "explanation": "Symfony 7.0 removed support for docblock annotations for routing and validation, requiring the use of attributes instead." ⏎ }

{"answer": "yes", "explanation": "AssetMapper is a Symfony component that manages frontend assets using an import map (typically defined in importmap.php) without requiring Node.js or a bundler like Webpack."}

{ ⏎   "answer": "no", ⏎   "explanation": "Symfony 6.4 is a Long-Term Support (LTS) release, supported until March 2027." ⏎ }

{"answer": "no", "explanation": "Symfony major versions are based on semantic versioning, which mandates the removal of deprecated features introduced in previous major versions."}

```json ⏎ {"answer": "yes", "explanation": "Yes, Symfony provides UPGRADE guides for each major release, documenting the breaking changes and improvements to assist developers in upgrading their projects."} ⏎ ```

{"answer": "Webpack Encore", "explanation": "Symfony's Webpack Encore component (now part of Symfony UX) allows managing assets and using import maps without requiring a separate Node.js or Webpack configuration by leveraging its built-in tools."}

{"answer": "no", "explanation": "Symfony follows a yearly release cycle (major releases in November of odd years like 7.1 in 2024, 7.3 in 2025, 8.1 in 2026), so a minor release like 8.2 would not exist in November 2026; furthermore, Symfony 8.0 is expected to be released around November 2025, making 8.1 the likely version in Nov 2026."}

{"answer": "no", "explanation": "Symfony typically releases new major versions in May (e.g., 7.2 in May 2024, 8.0 in May 2025), so a major release in November 2026 contradicts the standard May/November LTS and non-LTS release calendar structure."}

```json ⏎ {"answer": "8.2", "explanation": "According to Symfony's standard versioning release cycle, the minor version 8.2 is scheduled to follow 8.1."} ⏎ ```

{"answer": "no", "explanation": "Symfony uses a feature freeze and LTS (Long-Term Support) model where major version numbers (like 7.0, 8.0) typically only introduce deprecations or minor breaking changes with strong upgrade paths, rather than requiring a complete rewrite of applications."}

{"answer": "yes", "explanation": "Following Semantic Versioning and PHP's commitment to backward compatibility, minor version updates (e.g., 8.1 to 8.2) do not remove or change existing functionality, ensuring code written for the previous minor version continues to work."}

{"answer": 8.4, "explanation": "Symfony 8.4 is the final minor release in the 8.x series before the major 9.0 release."}

{ ⏎   "answer": "no", ⏎   "explanation": "Symfony versions follow a different numbering scheme than PHP; Symfony 8.2 does not exist, and even the latest Symfony versions (like 7.x) do not mandate PHP 8.5." ⏎ }

{"answer": "yes", "explanation": "Symfony follows a policy where deprecated features are kept for at least two major versions, so deprecations added in 8.x remain in 9.x."}

```json ⏎ {"answer": "no", "explanation": "Twig does not allow calling arbitrary PHP code directly inside `{{ }}`; it only supports Twig expressions and variables."} ⏎ ```

{"answer": "yes", "explanation": "Twig has auto-escaping enabled by default for the 'html', 'js', 'css', 'url', and 'attr' contexts to prevent XSS attacks."}

{"answer": "yes", "explanation": "The Twig `|e` filter performs HTML entity encoding by default to prevent XSS attacks when outputting data in an HTML context."}

```json ⏎ { ⏎   "answer": "localizednumber", ⏎   "explanation": "The filter `localizednumber` in twig/intl-extra is designed to format a number according to a specific locale." ⏎ } ⏎ ```

{"answer": "yes", "explanation": "The |raw filter in Laravel Blade templates explicitly marks a value as safe, bypassing HTML entity escaping."}

{"answer": "yes", "explanation": "In Twig, {{ }} is used for printing expression values, while {% %} is used for executing structural tags like conditions, loops, and variable assignments."}

{"answer": "no", "explanation": "Twig templates can use the 'set' tag to declare and assign variables directly within the template logic."}

{"answer": "dump", "explanation": "The 'dump' function in Twig outputs the debug structure of variables like arrays and objects."}

{"answer": "yes", "explanation": "Bootstrap is primarily a frontend library providing CSS and JavaScript components for styling and interactivity, but it does not provide the architecture, routing, or state management required to be considered an SPA framework like Angular or React."}

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

{"answer": "no", "explanation": "Bootstrap 4+ uses CSS Flexbox and a 12-column grid system, not floats or 16 columns."}

{"answer": "no", "explanation": "In Bootstrap 5, the default named breakpoints with infixes are sm, md, lg, xl, and xxl, which indeed total five; however, strictly speaking, 'xs' is also a valid conceptual breakpoint (though it has no infix), but the prompt specifies 'infix used in class names', so the list sm, md, lg, xl, xxl is correct for Bootstrap 5. Wait, let me double-check. Bootstrap 4 had sm, md, lg, xl (4). Bootstrap 5 added xxl, making it sm, md, lg, xl, xxl (5). So the statement is True for Bootstrap 5. However, the question asks 'True or false?' without specifying the version. Given the current standard (Bootstrap 5), the statement is true. Let me re-read carefully: 'Bootstrap's named breakpoints ... are sm, md, lg, xl, xxl — five of them.' This is accurate for Bootstrap 5. If the context implies the latest version, it is true. But often these questions might refer to Bootstrap 4 or be tricky. Let's assume Bootstrap 5 is the current standard. So 'yes'.\n\nCorrection: Actually, looking at standard knowledge bases, Bootstrap 5 defines 5 breakpoints (sm, md, lg, xl, xxl). The statement is True."}

{"answer": "yes", "explanation": "In Bootstrap (and similar CSS frameworks), spacing utilities map numeric values to multiples of the base spacing variable ($spacer)."}

{"answer": "data-bs-toggle", "explanation": "The data-bs-toggle attribute is used in Bootstrap 5 to activate interactive components like dropdowns, collapse, and popovers."}

{"answer": "yes", "explanation": "Bootstrap 5 removed the dependency on jQuery and uses its own vanilla JavaScript implementation for its components."}

{"answer": "yes", "explanation": "In Bootstrap 5, dark mode is enabled by adding the .dark class to the <html> element (the root of the document) via the data-bs-theme attribute or legacy .dark class support in v5.2+."}

```json ⏎ {"answer": "no", "explanation": "Doctrine ORM does not automatically create database tables; schema management typically requires separate tools like migrations or command-line schema updates."} ⏎ ```

{"answer": "persist", "explanation": "The persist() method in Doctrine's EntityManager transitions an entity to the managed state and schedules it for insertion, but SQL is only executed upon flush()."}

{"answer": "no", "explanation": "In Doctrine ORM, the method is called `merge()`, but it returns a *managed* instance of the entity; it does not necessarily make the *passed* object managed (the passed object remains detached/unchanged). Additionally, while `merge()` exists in Doctrine ORM, the statement is misleading because `merge()` returns a new managed instance rather than managing the original passed object."}

{"answer": "yes", "explanation": "DQL (Doctrine Query Language) is an object-oriented query language that abstracts database tables and columns into entities and their persistent fields."}

```json ⏎ {"answer": "null", "explanation": "In Doctrine ORM, Repository::find() returns null when no entity with the given ID is found."} ⏎ ```

{"answer": "yes", "explanation": "By default, the DoctrineBundle in Symfony is configured to call EntityManager::flush() during the 'kernel.response' event to persist pending changes."}

{"answer": "yes", "explanation": "Doctrine's Unit of Work automatically detects changes to managed entities during flush(), eliminating the need for an explicit persist() call for modifications."}

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

{"answer": "no", "explanation": "MVCC allows readers and writers to proceed concurrently without blocking each other, as readers see a consistent snapshot of the data."}

{"answer": "EXPLAIN", "explanation": "The EXPLAIN command displays the execution plan of a query without actually running it."}

{"answer": "yes", "explanation": "In PostgreSQL, SERIAL is an implementation detail that creates a sequence and sets a default value, while IDENTITY columns are standard SQL mechanisms for auto-generating values; both serve the same purpose of automatic value generation, making them functionally equivalent names for the same mechanism in common parlance."}

{"answer": "no", "explanation": "In PostgreSQL, UNIQUE constraints treat NULL values as distinct from each other, allowing multiple rows with NULL in the column."}

{"answer": "string_agg", "explanation": "The string_agg() function in PostgreSQL concatenates input values, which must be strings, in an arbitrary order and inserts a separator between adjacent input values."}

{"answer": "no", "explanation": "A plain VACUUM marks dead tuples for reuse but does not return the space to the operating system; only VACUUM FULL (or VACUUM with FULL option) truncates the file and returns space."}

{"answer": "PARTITION BY", "explanation": "The PARTITION BY clause divides the result set into groups (partitions) for the window function to operate on."}

{ ⏎   "answer": "no", ⏎   "explanation": "READ COMMITTED protects against dirty reads but allows non-repeatable reads; to protect against non-repeatable reads, one must use REPEATABLE READ or higher." ⏎ }

{"answer": "yes", "explanation": "In PostgreSQL, if no explicit BEGIN transaction is used, each individual SQL command is automatically committed immediately upon success, which is known as autocommit."}

{"answer": "COMMIT", "explanation": "COMMIT finalizes and saves all changes made during the current transaction."}

{"answer": "yes", "explanation": "Database indexes are used by the query optimizer to efficiently locate rows for any operation involving search conditions, including SELECT, UPDATE, and DELETE statements."}

{"answer": "yes", "explanation": "PostgreSQL supports SAVEPOINTs within transactions, allowing partial rollbacks of statements up to a specific savepoint."}

{"answer": "no", "explanation": "EXPLAIN ANALYZE actually executes the query and measures the time for each step, whereas EXPLAIN (without ANALYZE) only shows the plan without execution."}

{"answer": "pgvector", "explanation": "pgvector is a PostgreSQL extension that adds support for vector similarity search."}

{"answer": "no", "explanation": "Partial indexes are a feature of PostgreSQL, not PHP; PHP is a server-side scripting language and does not directly support database DDL syntax like CREATE INDEX."}

{"answer": "no", "explanation": "PostgreSQL uses Multi-Version Concurrency Control (MVCC) and Serializable Snapshot Isolation (SSI), not row locking, to ensure serializability."}

```json ⏎ { ⏎   "answer": "yes", ⏎   "explanation": "HTTP status code 201 (Created) signifies that the request has been fulfilled and a new resource has been created as a result." ⏎ } ⏎ ```

```json ⏎ {"answer": 204, "explanation": "HTTP status 204 indicates a successful request with an empty response body."} ⏎ ```

```json ⏎ {"answer": "yes", "explanation": "Per the HTTP specification, the DELETE method is considered idempotent, meaning that repeating the same request does not change the outcome of the first request."} ⏎ ```

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

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

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

{"answer": "Content-Type", "explanation": "The Content-Type header field specifies the media type (MIME type) of the entity body being sent."}

{ ⏎   "answer": "yes", ⏎   "explanation": "RFC 5789 explicitly states that the PATCH method is not idempotent by default, whereas PUT is required to be idempotent per RFC 7231." ⏎ }

{"answer": "no", "explanation": "Using == allows timing attacks and may trigger loose type juggling; hash_equals() should be used for constant-time comparison."}

{"answer": "yes", "explanation": "CSRF tokens are indeed server-generated, typically tied to the user's session, and validated server-side on state-changing requests to prevent cross-site request forgery."}

{"answer": "Content-Security-Policy", "explanation": "The Content-Security-Policy HTTP response header defines a set of rules that specify which sources the browser is allowed to load."}

```json ⏎ { ⏎   "answer": "no", ⏎   "explanation": "OAuth 2.0 is primarily an authorization protocol for granting access to resources, not authentication for identifying users (that's OpenID Connect, which layers on top of OAuth)." ⏎ } ⏎ ```

{"answer": "no", "explanation": "Validating input on the server is a good practice for data integrity, but it does not prevent XSS; preventing XSS requires output encoding/escaping when rendering data in the browser."}

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

{"answer": "yes", "explanation": "Refresh tokens are designed with a longer expiration time than access tokens and are specifically used to request new access tokens without requiring the user to re-authenticate."}

```json ⏎ { ⏎   "answer": "no", ⏎   "explanation": "Salts are designed to be stored publicly alongside the hash to prevent rainbow table attacks; only the hash and the original password are secret." ⏎ } ⏎ ```

{"answer": "no", "explanation": "PHPUnit requires test classes to extend PHPUnit\\Framework\\TestCase to function properly."}

{"answer": "no", "explanation": "In PHPUnit, setUp() runs before each individual test method, while setUpBeforeClass() runs once before all tests in the class."}

```json ⏎ {"answer": "yes", "explanation": "A data provider can indeed provide a single set of arguments for a test, just as it can provide multiple sets."} ⏎ ```

{"answer": "expectException", "explanation": "The expectException method in PHPUnit is used to set an expectation that a specific exception class will be thrown."}

{"answer": "no", "explanation": "The definitions are reversed; mocks verify interactions (calls) and stubs return predefined data without verification."}

```json ⏎ {"answer": "yes", "explanation": "In PHPUnit 10, the @dataProvider annotation was deprecated in favor of the PHP 8 attribute #[DataProvider]."} ⏎ ```

```json ⏎ {"answer": "no", "explanation": "PHPUnit allows tests to depend on each other through the @depends annotation or the depends() method, which means the statement is false."} ⏎ ```

{"answer": "--random-order", "explanation": "The --random-order flag shuffles the order in which tests are executed."}

{"answer": "3-4", "explanation": "intdiv(7, 2) is 3 and intdiv(-7, 2) is -4, concatenated to form the string '3-4'."}

{"answer": 9, "explanation": "In PHP, the exponentiation operator (**) has lower precedence than the unary minus operator (-), so -3 ** 2 is evaluated as -(3 ** 2), which is -9, but the output is 9 because the echo statement prints the result of the expression, and -3 ** 2 is parsed as (-3) ** 2 = 9."}

{"answer": "true", "explanation": "In PHP, '1e1' is compared numerically to 10 because both are numeric strings, and since 1e1 equals 10, the condition is true."}

{"answer": "other", "explanation": "In PHP, the switch statement uses loose comparison (==) for cases, so 'a' == 0 is false (since 'a' is not empty and not numeric), leading to the default case which echoes 'other'."}

{"answer": "abc", "explanation": "strtr only replaces characters or substrings in order of length, but since 'a' is a single character and 'ab' is two, 'a' is replaced first, then 'b' and 'c' remain, resulting in 'abc'."}

{"answer": "[hello]", "explanation": "When the offset is negative and its absolute value is greater than the string length, PHP returns the entire string starting from the beginning."}

```json ⏎ {"answer": "k,n,m", "explanation": "The '+' operator merges arrays keeping keys from the left array if they exist, resulting in keys 'k', 'n', 'm'."} ⏎ ```

{"answer": "xyz", "explanation": "The array is sorted by the third element (index 2), resulting in order [1,'x',2], [2,'y',1], [3,'z',2] because 1 < 2, then [1] vs [2] and [2] vs [2] keeps stable order? Wait, values at index 2 are 2, 1, 2. Sorting by index 2: [2,'y',1] (val 1) first, then [1,'x',2] and [3,'z',2] (both val 2). Since <=> returns 0 for equal, their relative order depends on the sort stability. PHP usort is not stable in older versions, but in PHP 8.0+ it is stable. Assuming stable sort: [2,'y',1], [1,'x',2], [3,'z',2']. So column 1 gives 'y', 'x', 'z' -> 'yxz'. Let me re-evaluate: original indices: 0:[1,'x',2], 1:[2,'y',1], 2:[3,'z',2]. Key for sort: index[2]: 2,1,2. Sorted order by key: index 1 (key 1), then index 0 (key 2), then index 2 (key 2) if stable. So order: [2,'y',1], [1,'x',2], [3,'z',2]. Column 1: 'y','x','z' -> 'yxz'."}

{"answer": "4", "explanation": "The function f is defined to accept parameters $a and $b. When using named arguments, 'a' => 5 sets $a to 5, and 'b' => 1 sets $b to 1, regardless of the order they appear in the array. The function returns 5 - 1, which equals 4."}

{"answer": 3, "explanation": "PHP does not support first-class callables for instance methods using the ... syntax in this context; however, assuming the question implies a valid first-class callable syntax (like $p->g(...)) which actually throws a parse error or is not standard, but if we interpret it as a standard closure or if the syntax were valid to capture the object, the object state is captured. In reality, PHP 8.1+ allows first-class callable syntax $p->g(...). When $p is set to null, the object $p is destroyed. However, the closure created by the first-class callable syntax holds a reference to the object. Therefore, the object is not destroyed when $p=null. The method g() returns $this->v which is 3. Thus, it outputs 3."}

```json ⏎ { ⏎   "answer": "B", ⏎   "explanation": "The static::class keyword inside a method returns the name of the class that was actually called (late static binding), which in this case is B." ⏎ } ⏎ ```

{"answer": 10, "explanation": "In PHP 8.5 (assuming experimental features or future RFCs regarding property hooks), the set hook multiplies the assigned value by 2 and stores it, so accessing $c->x returns 10."}

{"answer": "BA", "explanation": "The 'insteadof' clause makes TB::f the default for f(), while 'as' creates a new method g that calls TA::f."}

{ ⏎     "answer": "1", ⏎     "explanation": "Static properties in traits are shared among all classes that use the trait, so setting CX::$n also changes CY::$n." ⏎ }

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

```json ⏎ {"answer": "second", "explanation": "The finally block's LogicException replaces the inner RuntimeException, which is then caught by the outer catch block."} ⏎ ```

{"answer": "N\\App\\Foo|Baz", "explanation": "Baz is an alias for App\\Foo, so Baz::class resolves to N\\App\\Foo (current namespace N), and \\Baz::class resolves to the global Baz."}

```json ⏎ {"answer": "noyes", "explanation": "The first class_exists($c) returns false because 'Foo' doesn't exist in the global namespace, while class_exists(__NAMESPACE__ . '\\' . $c) returns true because 'Ns\\Foo' exists."} ⏎ ```

{"answer": "1,2,99", "explanation": "Iterating with a reference ($v) in foreach leaves $v bound to the last element of the array, so setting $v to 99 modifies that last element directly."}

{"answer": 3, "explanation": "Static variables in PHP are shared across all instances of a class, including subclasses, so each call to inc() increments the same counter."}

```json ⏎ {"answer": "11", "explanation": "The generator function yields 1, then when 10 is sent to it, $x becomes 10, and the function returns $x + 1, which is 11."} ⏎ ```

{"answer": "1,2", "explanation": "The outer generator delegates to inner via yield from, yielding 1 and 2 directly to the consumer before the return value of inner is assigned to $r and yielded, but iterator_to_array stops collecting values once the generator ends; however, in PHP 8+, the return value of a generator is not yielded but can be retrieved, and yield from passes through yielded values. Actually, let's re-evaluate: yield from yields all values from the inner generator (1, 2) and captures its return value in $r. Then outer yields $r ('ok'). So the sequence of yielded values from outer() is 1, 2, 'ok'. But wait, the question asks for the output of implode(',', iterator_to_array(outer())). iterator_to_array collects all values yielded by the generator. So it should be 1, 2, 'ok'. However, looking at standard behavior: yield from yields all values from the delegated generator and then the return value of the delegated generator is assigned to the left-hand side. The outer generator then yields that return value. So the yielded values are 1, 2, and 'ok'. implode will produce '1,2,ok'. But let me double-check: In PHP, when you use yield from, all values yielded by the inner generator are passed through to the caller of the outer generator. The return value of the inner generator is available as the result of the yield from expression. So outer yields 1, 2 (from inner), then yields 'ok' (the return value of inner). So the array is [1, 2, 'ok'] and implode gives '1,2,ok'. But the expected answer format is a string. Let me verify with PHP docs: yield from passes through all yielded values and the return value is captured. So the output is 1,2,ok."}

{"answer": "nonoyes", "explanation": "The first call returns false (no) because the cost matches, while the second returns true (yes) because cost 5 is higher than the hashed cost of 4."}

{"answer": "strict-in", "explanation": "E_ALL is typically 32767 (or higher), which includes the E_STRICT (2048) bit, so the bitwise AND is non-zero."}

```json ⏎ {"answer": "mapped", "explanation": "Symfony's Request::create converts 'HTTP_X_TOKEN' to 'X-Token' in the headers collection."} ⏎ ```

```json ⏎ { ⏎   "answer": "CBA", ⏎   "explanation": "Symfony's EventDispatcher calls listeners in reverse order of their priority; higher priority numbers execute first, so priority 10 (B) runs before default (0) for A, and priority 5 (C) runs after B but before A, resulting in 'B' then 'A' then 'C'? Wait, let's re-verify: Higher priority runs first. Priority 10 (B) is highest, runs first. Priority 5 (C) is next, runs second. Priority 0 (A) is lowest, runs last. So output is B C A. Wait, my initial guess was wrong. Let's trace: Priority 10: B. Priority 5: C. Priority 0: A. Output: B C A. No, that's not right either. The documentation states listeners with higher priority are invoked first. So 10 (B) -> 5 (C) -> 0 (A). Result: B C A. Wait, I need to be certain. Symfony EventDispatcher priority: 'Listeners with a higher priority are executed first.' So order is 10, 5, 0. Output is 'BCA'. I will correct the answer." ⏎ } ⏎ ```

{"answer": "same", "explanation": "Doctrine ORM maintains a first-level cache (identity map) per EntityManager; calling find with an existing ID for a managed entity returns the exact same instance from the cache rather than creating a new object."}

{"answer": "0", "explanation": "Since the entity is persisted and then removed before flush, the final flush operation results in no database rows being inserted, so the count is 0."}

{"answer": "1", "explanation": "The COUNT() aggregate function counts non-null values, so it returns 1 for the table containing one integer and one NULL."}

{"answer": "10,30,60", "explanation": "The subquery calculates the cumulative sum of x (10, 30, 60), and string_agg concatenates them in id order."}

```json ⏎ {"answer": "M1M2", "explanation": "The middleware executes in the order they are added, printing 'M1' then 'M2' before passing control down the stack."} ⏎ ```

```json ⏎ {"answer": 11, "explanation": "The message bus processes the message through both handlers, incrementing $n by 1 and then by 10, resulting in 11."} ⏎ ```

{"answer": 1, "explanation": "The first INSERT succeeds, the second is ignored due to the unique constraint and ON CONFLICT DO NOTHING, leaving one row."}

```json ⏎ {"answer": 1, "explanation": "The second insert of the same value violates the deferred uniqueness constraint at transaction end, but within the transaction, only one row is inserted successfully."} ⏎ ```

{"answer": 4, "explanation": "The --filter option matches the method name 'test_sum', which matches both test_sum and test_sum_abs (as it is a substring match). Each of these two methods is invoked with 3 data sets from the data provider, resulting in 2 * 3 = 6 potential tests? Wait, let's re-evaluate standard filter behavior. In PHPUnit, --filter uses a regular expression. 'test_sum' matches 'test_sum' and 'test_sum_abs'. So 2 methods. Each method has 3 data sets. So 2 * 3 = 6 tests. Let me double check if 'test_sum' matches 'test_sum_abs'. Yes, standard regex search finds 'test_sum' inside 'test_sum_abs'. So 6 tests.\n\nCorrection: The filter is a regex. `test_sum` matches `test_sum` (1 method) and `test_sum_abs` (1 method). Total 2 methods. Each has 3 data points. Total 6 tests."}

{"answer": "2,1", "explanation": "The data provider yields two test cases ([1] and [-1]), so 2 tests are run. The assertion `$x > 0` fails for the case where x is -1, resulting in 1 failure."}

{"answer": "POST", "explanation": "The -d option in curl sends data in the request body, which defaults the HTTP method to POST."}

```json ⏎ {"answer": "GET", "explanation": "The -G flag in curl specifies that the -d option should be used in a GET request, sending the data in the query string."} ⏎ ```

{"answer": "invalid_request", "explanation": "According to RFC 6749 Section 5.2, if the client authentication fails or the client_id is missing/invalid, the authorization server must return 'invalid_request' as the error code."}

{"answer": "fragment", "explanation": "In the implicit grant flow (response_type=token), the access token is passed in the URI fragment (the part after the hash #) of the redirect_uri to prevent it from appearing in server logs or referrer headers."}

{"answer": 0, "explanation": "In Twig, the 'default' filter only replaces null values or undefined variables with the default; false is a valid value, so the expression evaluates to false * 3, which results in 0."}

```json ⏎ { ⏎   "answer": "string", ⏎   "explanation": "In Twig, the `~` operator concatenates values into a string, and `1 + 2` evaluates to an integer, but since it is concatenated with 'a', the final result is a string." ⏎ } ⏎ ```

{"answer": 1, "explanation": "The array contains an empty string, which violates the NotBlank constraint, resulting in one violation."}

{"answer": "invalid", "explanation": "A Symfony form created without any fields or specific validation constraints that require data to be present is considered valid by default when isValid() is called, assuming no data was submitted that triggered errors. However, in Symfony, an empty form is valid. Wait, let me re-verify. Symfony documentation states that a form is valid if all its fields are valid. If there are no fields, it is valid. Therefore, $form->isValid() returns true. The output is 'valid'."}

{"answer": "same", "explanation": "Symfony's Container caches service instances by default, so two get() calls for a private/public service within the same container lifecycle return the same object instance."}

{"answer": "hi Bob!", "explanation": "Symfony's parameter resolution recursively replaces placeholders like %name% and %greeting%, resulting in 'hi Bob!'."}

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

{"answer": "text-primary", "explanation": "In CSS, when multiple classes with the same specificity (utility classes) are applied to an element, the last one defined in the stylesheet takes precedence; since .text-primary is listed after .text-danger in the class attribute and typically later in the Bootstrap CSS file order (or due to source order tie-breaking if equal specificity), .text-primary wins."}

{"answer": 2, "explanation": "The Domain layer is allowed to depend only on itself. Importing App\\Application\\PlaceOrder and App\\Infrastructure\\Db creates two distinct dependency violations against the defined rules."}

```json ⏎ {"answer": 2, "explanation": "The Domain layer can only depend on the Domain layer; however, it depends on both PlaceOrder (Application) and Db, Logger (Infrastructure), resulting in two violations."} ⏎ ```

{"answer": "10,15", "explanation": "$a remains 10, $c is a new Money object with amount 15 (10+5); concatenating with comma gives '10,15'."}

{"answer": "1", "explanation": "The 'add' method increments the count, and 'remove' throws an exception before unsetting the item due to the count check, leaving the count at 1."}

{"answer": "hi", "explanation": "The code creates an instance of class C and calls the hi() method, which returns the string 'hi'. This behavior is consistent across PHP versions including 8.x."}

{"answer": "yesno", "explanation": "The first check returns true because the lazy ghost is uninitialized, outputting 'yes'. Accessing the property $v triggers the initialization callback which sets $v to 21. The second check then returns false because the object has been initialized, outputting 'no'."}

{ ⏎   "answer": "no", ⏎   "explanation": "The Guard authentication system was deprecated in Symfony 5.3 and removed in Symfony 7.0, so the class does not exist in Symfony 8.1." ⏎ }

{"answer": "noyes", "explanation": "In Symfony 7.0, the AnnotationClassLoader was removed in favor of AttributeClassLoader; therefore, the first class does not exist (false -> 'no'), while the second does exist (true -> 'yes')."}