Sobes.tech
Middle

How does the 'new' operator work in C++?

sobes.tech AI

Answer from AI

The new operator allocates memory for an object or array of objects on the heap and returns a pointer to the allocated memory.

Process:

  1. Memory allocation: The appropriate memory allocation function is called. For a single object, operator new(size_t); for an array, operator new[](size_t). These functions allocate raw memory by default.
  2. Constructor call: If an object is being allocated (not just raw memory), the corresponding constructor is called to initialize the object. For arrays, constructors are called for each element.
  3. Pointer return: The new operator returns a typed pointer to the beginning of the allocated and initialized memory.

Example of allocating a single object:

// Allocate memory for an object of type MyClass and call its default constructor
MyClass* obj = new MyClass();

Example of allocating an array of objects:

// Allocate memory for an array of 10 MyClass objects and call their default constructors
MyClass* arr = new MyClass[10];

To deallocate memory allocated with new, the delete operator is used. For arrays, delete[]. Incorrect use of delete or delete[] leads to undefined behavior.

Overloading operator new and operator delete allows customizing the memory allocation and deallocation process.