Where Do Objects Reside in Memory: Stack, Heap, or Somewhere Else?

Stack vs. Heap Object Creation

The question poses concerns about object creation on the stack or heap. While the code provided (Object o:) implies object creation on the stack, it does not explicitly mention stack or heap. Let's clarify this distinction.

In C , the location of an object in memory is determined by its storage duration, not stack or heap specifically. There are four storage durations: automatic, dynamic, static, and thread-local. Automatic storage is primarily used for local variables on the call stack, while dynamic storage is used for objects allocated on the heap with 'new'.

• Stack: Automatic storage, typically reserved for local variables.
• Heap: Dynamic storage, used for objects created with 'new'.
• Static Memory: Static (or thread-local) objects reside in neither stack nor heap, usually in a separate region.

Object Creation

• Object o; // Local variable with automatic storage (stack)
• Object o = Object(); // Dynamic storage (heap)
• Object* o; // Pointer to an object with automatic storage (stack)
• Object* o = new Object(); // Pointer to an object with dynamic storage (heap)

Context and Storage Duration

The storage duration of an object is determined by its context. For instance:

• foo.o: Member variable in a statically allocated object (neither stack nor heap)
• f.o: Member variable in a locally allocated object (stack)
• p->o: Member variable in a dynamically allocated object (heap)

Pointers and Storage

Pointers themselves are objects and follow the same storage rules. Their storage is determined by their context, not the type they point to. The type they point to determines the storage duration of the pointed object.

Overall, understanding storage duration is crucial for comprehending memory management in C . Objects can reside in different memory regions depending on their storage duration and context.

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