D Questions and Answers for Viva

Answer-1: D is a high-level, statically-typed, and compiled programming language designed for system and application programming.

Answer-2: The D language was created by Walter Bright of Digital Mars in 2001.

Answer-3: Key features include garbage collection, modularity, native machine code compilation, and mixins.

Answer-4: D simplifies syntax, adds garbage collection, and offers better module management compared to C++.

Answer-5: D supports multiple paradigms, including imperative, object-oriented, and functional programming.

Answer-6: A module is a file containing D code, and each module acts as a separate namespace.

Answer-7: The file extension for D source files is .d.

Answer-8: Variables are declared with the syntax: dataType variableName;, for example, int x;.

Answer-9: Ranges are a key feature for iterating over collections efficiently, often used with D's algorithms.

Answer-10: Yes, D includes garbage collection for automatic memory management.

Answer-11: import is used to include modules, similar to #include in C++ or import in Python.

Answer-12: immutable declares that a variable's value cannot be changed after initialization.

Answer-13: D supports dynamic, static, and associative arrays, offering flexibility in data storage.

Answer-14: Templates allow generic programming by enabling code to be written without specifying data types.

Answer-15: A mixin allows embedding strings or code within other code, enabling meta-programming.

Answer-16: Functions are written as returnType functionName(parameters) { body }.

Answer-17: A struct is a user-defined type that groups related variables under one data structure.

Answer-18: unittest is a built-in feature for writing and running unit tests directly in the code.

Answer-19: Exceptions are handled using try, catch, and finally blocks, similar to Java or C#.

Answer-20: auto lets the compiler infer the variable's type based on its initial value.

Answer-21: Yes, D supports both function and operator overloading.

Answer-22: alias creates an alternative name for an existing type or symbol, improving code readability.

Answer-23: A delegate is a function pointer that retains a reference to its enclosing environment.

Answer-24: D provides built-in libraries like std.concurrency for creating and managing threads.

Answer-25: A class is a reference type that supports inheritance and encapsulates data and methods.

Answer-26: struct is a value type, while class is a reference type with inheritance capabilities.

Answer-27: Interfaces are defined using the interface keyword and contain only abstract methods.

Answer-28: scope is used for managing resource cleanup, ensuring destructors are called as necessary.

Answer-29: Yes, D supports lambda expressions, written as (parameters) => expression;.

Answer-30: static is used to define members that belong to the type itself rather than an instance.

Answer-31: External libraries can be included using dub, D's package manager.

Answer-32: Traits provide compile-time reflection capabilities, allowing introspection of types.

Answer-33: scope(exit) executes a block of code when the enclosing scope is exited.

Answer-34: foreach iterates over collections, e.g., foreach(item; array) { body }.

Answer-35: Associative arrays map keys to values and are declared as dataType[keyType].

Answer-36: Yes, D supports modules natively, promoting modular programming.

Answer-37: Contracts allow specifying preconditions, postconditions, and invariants in code.

Answer-38: The default visibility of members is private.

Answer-39: D supports functional programming with features like higher-order functions, immutability, and ranges.

Answer-40: CTFE (Compile-Time Function Execution) allows functions to execute at compile time.

Answer-41: A ref parameter passes a variable by reference, allowing modifications to the original value.

Answer-42: The pure keyword marks functions as free of side effects, ensuring they depend only on input arguments.

Answer-43: shared indicates that a variable can be safely accessed by multiple threads.

Answer-44: D provides a rich set of functions for string manipulation in the std.string module.

Answer-45: A lazy parameter delays evaluation of its argument until it is used in the function.

Answer-46: synchronized is used for locking and thread synchronization in multithreaded code.

Answer-47: immutable ensures the value never changes, while const allows the value to change outside its scope.

Answer-48: Templates enable generic and reusable code that adapts to different data types.

Answer-49: Yes, D supports RAII (Resource Acquisition Is Initialization) for resource management.

Answer-50: Use the dmd compiler: dmd file.d -o executable.