In context C++, the process of individually copying each member of an object to the corresponding member of another object of the same class is known as _______ copying.

Question

Accepted Answer

The correct option is (2):
In C++ and other object-oriented languages, the process of simply copying the values of all member variables from one object to another is formally known as **shallow copying**. This mechanism, often implemented by the compiler's automatically generated default copy constructor or assignment operator, performs a literal member-wise copy. For primitive data types like integers or floats, the value is perfectly duplicated. However, the term 'shallow' is crucial because of its behavior with pointer members: only the memory address stored in the pointer itself is copied, not the data residing at that address on the heap. This means both the original and the newly copied object end up pointing to the exact same block of dynamically allocated memory, which is the defining characteristic of shallow copying and can lead to critical runtime issues like double deletion.

The incorrect option is (1):
**mutable** is a C++ keyword, not a type of copying. Its purpose is to allow a specific non-static data member of a class to be modified even if the object containing it is declared `const`. This feature helps to maintain the object's "logical constness" from an external view while permitting necessary internal modifications, such as updating a cache counter or a synchronization mutex. It governs write access to an individual member within a `const` function and is entirely unrelated to the fundamental member-to-member duplication process described in the question, thus making it an incorrect answer choice.

The incorrect option is (3):
**respective** is a general English adjective, meaning 'belonging or relating separately to each of two or more things,' and is not a technical term for a copying process in C++ programming. While the data members are indeed copied to their *respective* counterparts, the widely accepted, technical terminology used to classify this behavior—based on how it handles dynamically allocated memory and pointers—is **shallow copying**. Using a common descriptive word like 'respective' instead of the precise, established term is inaccurate in a computer science context.

The incorrect option is (4):
**default** refers to the *mechanism* used, not the name of the *process* itself. The compiler automatically provides a *default* copy constructor and a *default* assignment operator, and these *default* functions are what *perform* the **shallow copy** behavior. The question asks for the name of the *process* of individual member copying, which is the definition of **shallow copying**. In contrast, if a programmer defines their own copy constructor to perform a deep copy, that user-defined function would then become the 'default' for that class, which further shows why 'default' is an imprecise descriptor for the behavior.