C + + Object-oriented model

1. Basic knowledge

How does the C + + compiler accomplish the transformation of object-oriented theory to computer programs?
In other words: how the C + + compiler manages relationships between classes, objects, classes, and objects
Specifically, the specific object calls the method of writing the class, that is, how the C + + compiler distinguishes, is that specific class, call this method that?
Think about the results of the program

#include "iostream"usingNamespace Std;class c1{ Public:intI//4intJ//4intK//4protected:Private:};//sizeof calculates the size of this class asClass c2{ Public:intI//4intJ//4intK//4Static intM//4 Public:int GETK()  {returnK }//4 (in the C language, the function should generate a 4-byte function pointer pointing to it)voidSETK (intval) {k = Val;}//4protected:Private:};//sizeof calculates that the size of the class is also 12, not a (sizeof can only calculate the stack and the size of the heap, that is, m in the global zone, but the function does not actually have a corresponding pointer, then the program runs when each object to find its own function?) )intMain () {printf ("c1:%d \ n",sizeof(C1)); printf"c2:%d \ n",sizeof(C2)); System"Pause");}

2. Explain C + + properties and methods in four areas of memory
1) member variables and member functions in C + + class objects are stored separately
Member variables:
Normal member variables: stored in an object, with the same memory layout and byte alignment as the struct variable
Static member variables: stored in the global data area
member functions: stored in code snippets.
The problem is: many objects have a common piece of code? How does the code differentiate between specific objects?

In other words: int getk () {return k;}, how does the code differentiate between specific obj1, OBJ2, and Obj3 object K values?

2) C + + compiler internal processing of ordinary member functions (and its importance, the diagram is not clear to see)

Test T =====> Test (this,1,2) ====> test (&t,1,2)

3. Summary:
1. member variables and member functions in C + + class objects are stored separately. Memory four-zone model in C language still works!
2. The normal member function of a class in C + + implicitly contains a pointer to the current object.
3. Static member function, member variable belongs to class
4. The difference between a static member function and an ordinary member function:
Static member functions do not contain pointers to specific objects
The normal member function contains a pointer to a specific object

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C + + Object-oriented model