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Question 1. Which of the following statements about Delphi’s Automatic Reference Counting (ARC) is correct? A) ARC is enabled for all desktop applications. B) ARC only works with interfaces, not with class instances. C) ARC automatically frees an object when its reference count reaches zero, but only on mobile platforms. D) ARC requires the programmer to call Free explicitly for every object. Answer: C Explanation: ARC is applied to Delphi mobile platforms (iOS, Android) and automatically releases objects when their reference count drops to zero. Desktop Delphi uses manual memory management (except for interfaces). Question 2. In Delphi, what is the effect of declaring a method as “virtual; abstract;”? A) The method provides a default implementation that can be overridden. B) The method must be overridden in descendant classes and has no implementation in the base class. C) The method cannot be overridden by descendants. D) The method can be called without an instance of the class. Answer: B Explanation: “virtual; abstract;” declares a pure virtual method – it has no body and forces descendants to provide an implementation. Question 3. Which of the following is true about method shadowing in Delphi? A) Shadowed methods are invoked through the override keyword. B) Shadowing occurs when a descendant declares a method with the same name but without override or reintroduce. C) Shadowed methods are always virtual.
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D) Shadowing is only allowed for class constructors. Answer: B Explanation: If a descendant declares a method with the same name as an inherited one without using override or reintroduce, the new method hides (shadows) the inherited one. Question 4. When implementing multiple interfaces in a Delphi class, which keyword ensures that each interface’s reference count is managed correctly? A) implements B) inherits C) reintroduce D) overload Answer: A Explanation: The implements directive tells the compiler to generate the necessary reference-counting code for each interface the class supports. Question 5. Which generic constraint guarantees that a type parameter can be instantiated with a parameterless constructor? A) constraint class B) constraint record C) constraint constructor D) constraint interface Answer: C Explanation: The constructor constraint requires that the generic type argument have a public parameterless constructor, allowing the code to call Create. Question 6. In an anonymous method that captures a local variable, what happens to the captured variable when the method is executed later on a different thread?
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Explanation: TRttiType.GetMethod returns a TRttiMethod object representing a method with the specified name, which can then be invoked. Question 9. Which of the following statements best describes the difference between the Delphi stack and heap? A) The stack is used for dynamic memory allocation, while the heap stores local variables. B) The stack grows automatically with object creation, the heap must be manually managed. C) The stack holds static and local variables with LIFO order; the heap stores objects allocated with New or Create and must be freed manually. D) The stack is only available on 64-bit targets. Answer: C Explanation: The stack stores fixed-size local variables and follows a last-in-first-out discipline. The heap is used for dynamically allocated objects and must be released with Free or Dispose. Question 10. In Delphi, which tool can be used to detect memory leaks in a complex object graph at runtime? A) FastMM4 memory manager with ReportMemoryLeaksOnShutdown enabled. B) CodeGear Profiler. C) Debug Window → Leaks. D) IDE → Project → MemoryCheck. Answer: A Explanation: FastMM4 (the default memory manager in recent Delphi versions) reports any leaked objects when ReportMemoryLeaksOnShutdown is set to True. Question 11. Which conditional define is automatically set when compiling a Delphi project for the Android platform?
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A) MSWINDOWS
B) LINUX
C) ANDROID
D) MACOS
Answer: C Explanation: The compiler defines ANDROID when the target platform is Android, allowing conditional compilation for that platform. Question 12. In a Delphi project group, which file type stores the list of projects and their build order? A) .dproj B) .dpr C) .dprojgroup D) .bpl Answer: C Explanation: .dprojgroup files describe a group of Delphi projects, including dependencies and build order. Question 13. When customizing the build process with MSBuild, which element allows you to execute a custom tool after compilation? A) B) C) D) Answer: A Explanation: The target in an MSBuild project file runs after the main compilation steps, enabling custom actions.
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Answer: B Explanation: Overriding WndProc allows a component to process any Windows message before the inherited VCL implementation. Question 17. In FireMonkey, which class is responsible for the GPU-accelerated rendering pipeline? A) TCanvas B) TForm C) TScene D) TControl Answer: C Explanation: TScene represents the root of the FMX rendering tree and orchestrates GPU-based drawing of all visual elements. Question 18. Which FMX property determines whether a control uses a style or a skin? A) StyleLookup B) SkinData C) StyleName D) SkinLookup Answer: A Explanation: StyleLookup specifies the style resource to apply; if left blank, the control uses its default skin. Question 19. When creating a new VCL component from scratch, which method must you override to ensure the component’s properties are streamed correctly? A) DefineProperties
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B) GetChildren C) ReadState D) WriteState Answer: A Explanation: DefineProperties allows a component to register custom property readers/writers for streaming to .dfm files. Question 20. Which design-time class is used to provide a custom property editor for a component’s property in the IDE? A) TComponentEditor B) TPropertyEditor C) TCustomEditor D) TDesignEditor Answer: B Explanation: TPropertyEditor descendants are registered with RegisterPropertyEditor to supply custom UI for editing a property at design time. Question 21. In Delphi, what is the default file extension for a compiled FireMonkey form’s resource stream? A) .dfm B) .fmx C) .dcu D) .fmxr Answer: B Explanation: FireMonkey forms are stored in .fmx files, which contain the streamed component hierarchy and property values.
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Explanation: TFDLocalSQL allows you to write SQL statements that operate on in-memory datasets such as TFDMemTable. Question 25. In a multi-tier DataSnap server, which class represents a method that can be invoked remotely? A) TDSServerModule B) TDataSnapMethod C) TDSServerClass D) TDSServerMethodInstance Answer: D Explanation: TDSServerMethodInstance encapsulates a method exposed to clients; the server creates an instance for each call. Question 26. Which attribute must be applied to a DataSnap method to indicate it should run in a separate thread? A) [ThreadSafe] B) [Async] C) [InvocationType(otAsync)] D) [ServerMethod] Answer: C Explanation: [InvocationType(otAsync)] specifies that the method should be invoked asynchronously on a worker thread. Question 27. When consuming a RESTful service with Delphi’s RESTClient library, which component is responsible for JSON serialization? A) TRESTRequest B) TRESTResponse
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C) TRESTClient D) TJSONMarshal Answer: D Explanation: TJSONMarshal (and its counterpart TJSONUnMarshal) handle conversion between Delphi objects and JSON payloads. Question 28. Which Indy component provides a high-performance TCP server implementation? A) TIdTCPClient B) TIdTCPServer C) TIdHTTPServer D) TIdSMTP Answer: B Explanation: TIdTCPServer listens for incoming TCP connections and manages client sockets in a scalable way. Question 29. In the Parallel Programming Library (PPL), which construct is used to wait for multiple tasks to complete and retrieve their results? A) Parallel.For B) Future C) Task.WaitAll D) Parallel.Async Answer: C Explanation: Task.WaitAll blocks until all supplied ITask instances have finished, allowing you to collect results afterwards.
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C) SHGetFolderPath D) GetEnvironmentVariable Answer: B Explanation: GetSystemDirectory returns the path of the system folder (e.g., C: Windows\System32). Question 33. When calling a function exported from a DLL that uses the stdcall calling convention, which attribute must be specified in the Delphi external declaration? A) cdecl B) stdcall C) safecall D) register Answer: B Explanation: The stdcall directive tells the compiler to generate code that matches the stdcall calling convention used by many Windows APIs. Question 34. Which Delphi package type is intended for design-time components that appear in the IDE’s component palette? A) Runtime package (BPL) B) Design-time package (BPL) C) Static library (LIB) D) Dynamic library (DLL) Answer: B Explanation: Design-time packages are loaded by the IDE to register components, property editors, and component editors.
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Question 35. In Indy, which property of TIdHTTP controls whether redirects (3xx responses) are followed automatically? A) HandleRedirects B) AllowRedirects C) RedirectsEnabled D) FollowRedirects Answer: A Explanation: TIdHTTP.HandleRedirects determines whether the component will automatically issue a new request for HTTP redirect responses. Question 36. Which Delphi class represents a JSON object that can be manipulated programmatically? A) TJSONObject B) TJSONValue C) TJSONPair D) TJSONNumber Answer: A Explanation: TJSONObject is a container for name/value pairs and provides methods to add, remove, and query JSON data. Question 37. When using the XML Document Object Model (DOM) in Delphi, which interface provides methods to navigate through nodes? A) IXMLNode B) IXMLDocument C) IXMLNodeList D) IXMLReader Answer: A
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D) [ComponentPlatforms] Answer: A Explanation: [Component] marks a class as a component, allowing the IDE to discover it via RTTI when the containing package is loaded. Question 41. In FireDAC, which option enables automatic reconnection to the database after a lost connection? A) ReconnectOnError=Yes B) MonitorBy=Remote C) PingOnExecute=Yes D) LoginPrompt=False Answer: A Explanation: ReconnectOnError=Yes tells the driver to attempt reconnection automatically when a communication error occurs. Question 42. Which method of TClientDataSet must be called to apply updates that have been cached locally back to the underlying database? A) ApplyUpdates B) CommitUpdates C) UpdateRecord D) Refresh Answer: A Explanation: ApplyUpdates writes the pending changes (inserts, updates, deletes) stored in the client dataset to the remote provider. Question 43. In a multi-threaded VCL application, which function should you call to safely update a visual control from a worker thread? A) PostMessage
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B) Synchronize C) Queue D) SendMessage Answer: B Explanation: Synchronize executes a method on the main UI thread, ensuring that VCL controls are accessed safely. Question 44. Which Windows API function is used to create a named mutex that can be shared across processes? A) CreateEvent B) CreateMutex C) OpenMutex D) InitializeCriticalSection Answer: B Explanation: CreateMutex creates or opens a mutex object identified by a name, allowing inter-process synchronization. Question 45. When building a Delphi DLL that exports a class, which directive should be used to expose the class’s methods? A) exports B) library C) public D) stdcall Answer: A Explanation: The exports section of a DLL lists the symbols (functions, procedures, or class factories) that are visible to external modules.
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Explanation: UpdateOptions.CacheSize determines how many rows are kept in the client-side cache for buffered updates. Question 49. Which Delphi attribute can be used to hide a class member from the Object Inspector at design time? A) [Hide] B) [DesignOnly] C) [NonPublished] D) [Ignore] Answer: C Explanation: [NonPublished] marks a property or method as not visible to the IDE’s Object Inspector. Question 50. In the Parallel Programming Library, which method creates a parallel loop that automatically balances work across available cores? A) Parallel.ForEach B) Parallel.For C) Parallel.Map D) Parallel.Reduce Answer: B Explanation: Parallel.For splits the index range into chunks and distributes them across worker threads, balancing load dynamically. Question 51. Which RTL unit provides the TMonitor class for implementing monitor-style synchronization? A) System.SyncObjs B) System.Classes
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C) System.Threading D) System.SysUtils Answer: A Explanation: System.SyncObjs defines TMonitor, TCriticalSection, TEvent, and other synchronization primitives. Question 52. When using TThread.CreateAnonymousThread, which method should you call to start the thread? A) Run B) Start C) Execute D) Resume Answer: B Explanation: Start launches the thread’s execution; the anonymous method passed to the constructor runs in the thread context. Question 53. Which registry hive contains per-user configuration data? A) HKEY_LOCAL_MACHINE B) HKEY_CLASSES_ROOT C) HKEY_CURRENT_USER D) HKEY_USERS Answer: C Explanation: HKEY_CURRENT_USER stores settings specific to the currently logged-in user. Question 54. In a Delphi package, which directive specifies that the package should be loaded at design time only?
