Does new always allocate on the heap in C++ / C# / Java

Question

My understanding has always been, regardless of C++ or C# or Java, that when we use the new keyword to create an object it allocates memory on the heap. I thou

Answer 1

I thought that new is only needed for reference types (classes), and that primitive types (int, bool, float, etc.) never use new

In C++, you can allocate primitive types on the heap if you want to:

int* p = new int(42);

This is useful if you want a shared counter, for example in the implementation of shared_ptr.

Also, you are not forced to use new with classes in C++:

void function()
{
    MyClass myObject(1, 2, 3);
}

This will allocate myObject on the stack. Note that new is rarely used in modern C++.

Furthermore, you can overload operator new (either globally or class-specific) in C++, so even if you say new MyClass, the object does not necessarily get allocated on the heap.