C / C++ / MFC

void SomeClass::SomeFunction()
{
  AnotherClass myClass; 

// myClass is declared on the stack, object is created and allocated automatically ( constructor is called. )
// Will be deleted/detroyed when reaching the end of the function. ( destructor of AnotherClass is called
}

void SomeClass::AnotherFunction()
{
  AnotherClass* pMyClass = NULL; // object is not allocated yet

  pMyClass = new AnotherClass; // object is now allocated ( constructor is called ).

  // at the end of the function, the memory allocated to pMyClass will not be free, a memory leak will happen, the object is not yet deleted, the destructor is not called; unless you explicitly delete the object

  delete pMyClass; // will call the destructor of AnotherClass.
}

void SomeClass::YetAnotherFunction()
{
 CDialog dlg;
 dlg.DoModal();

 // and the end of the function, the dlg object will be desctructed.
}

void SomeClass::YetAnotherFunction2()
{
 // modeless dialog.
 CDialog* pDlg;
 pDlg = new CDialog;
 pDlg->Create( /*...*/ );
 pDlg->ShowWindow(SW_SHOW);


 // and the end of the function, the pDlg object will be desctructed only if delete is called.

 // might not be kosher coding ... but you should get the idea...
 delete pDlg;
}