What's the Difference Between the C `new` Operator and `operator new`?

New Operator vs. Operator New: Demystifying the Differences

Differentiating between the "new operator" and "operator new" can be confusing. Here's an in-depth explanation to clarify the distinction.

Operator New: A Raw Memory Allocator

Operator new is a standard C function that allocates uninitialized memory from the heap. It operates similarly to the malloc() function but is specific to C .

You can invoke operator new directly to reserve raw memory:

char *x = static_cast<char *>(operator new(100));

Overloading operator new is possible, allowing you to customize memory allocation for specific classes or globally.

New Operator: Object Creation and Initialization

The "new operator" is the primary method used to create objects in C . It combines the functionalities of operator new and class constructors.

When you use the new operator:

my_class *x = new my_class(0);

It first calls operator new to allocate raw memory for the object my_class. Subsequently, it invokes the constructor my_class(0) to initialize the object within that memory. If the my_class contains embedded or base class objects, their constructors are also called.

Key Differences

The fundamental difference between the "new operator" and "operator new" lies in their behavior:

• Operator new: Allocates raw memory without any initialization.
• "New operator": Combines memory allocation via operator new with object construction through constructors.

In summary, operator new is a lower-level function for allocating raw memory, while the "new operator" is a higher-level abstraction that seamlessly handles memory allocation and object initialization.

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