Accessibility (1A) Young Won Lim 8/22/13

Transcription

1 Accessibility (1A)

2 Copyright (c) Young W. Lim. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". Please send corrections (or suggestions) to youngwlim@hotmail.com. This document was produced by using OpenOffice.

3 Private Access Specifier default access specifier the members of the same class friend classes and functions class CC { void main(void) { CC C1; C1.mem1; C1.func1 (); int foo(cc *X) { X->mem1; X->func1 (); the main function C-style functions int func3( ) { mem1; func1 (); of the same class class DD { int faa(cc *Y) { Y->mem1; Y->func1 (); of other classes class EE : public CC { int func4( ) { mem1; func1 (); of derived classes Accessibility 3

4 Protected Access Specifier the members of the same class friend classes or functions the members of derived classes void main(void) { CC C1; C1.mem2; C1.func2 (); int foo(cc *X) { X->mem2; X->func2 (); the main function C-style functions class CC { int func3( ) { mem2; func2 (); of the same class class DD { int faa(cc *Y) { Y->mem2; Y->func2 (); of other classes class EE : public CC { int func4( ) { mem2; func2 (); of derived classes OK Accessibility 4

5 Public Access Specifier class CC { also accessible whenever objects are visible void main(void) { CC C1; C1.mem3; C1.func3 (); int foo(cc *X) { X->mem3; X->func3 (); the main function C-style functions int func2( ) { mem3; func3 (); of the same class class DD { int faa(cc *Y) { Y->mem3; Y->func3 (); of other classes class EE : public CC { int func4( ) { mem3; func3 (); of derived classes OK Accessibility 5

6 Accessibility 6

7 Member Function Definition within a class int func1( ) { mem2 = 10; func2 (); mem3 = 10; func3 (); int func2( ) { mem1 = 10; func1 (); mem3 = 10; func3 (); int func3( ) { mem1 = 10; func1 (); mem2 = 10; func2 (); of the same class of the same class of the same class class CC { Each members can be accessed by other members of the same class Accessibility 7

8 Member Function Definition within a derived class class EE : public CC { int func4( ) { mem2; func2 (); mem3; func3 (); of derived classes class CC { The members of a derived class can access public and protected members of the base class Accessibility 8

9 Member Function Call from objects void main(void) { CC C1; C1.mem3; C1.func3 (); int foo(cc *X) { X->mem3; X->func3 (); class DD { int faa(cc *Y) { Y->mem3; Y->func3 (); the main function C-style functions of other classes class CC { Only public members can be accessed Accessibility 9

10 Abstract Class (2) Accessibility 10

11 Public Inheritance class CC { class EE : public CC { class EE : public CC { int mem4; int func4(); int mem4; int func4(); class FF : EE { : int mem5; int func5(); Accessibility 11

12 Protected Inheritance class CC { class EE : protected CC { class EE : protected CC { int mem4; int func4(); int mem4; int func4(); class FF : EE { : int mem5; int func5(); Accessibility 12

13 Private Inheritance class CC { class EE : private CC { int mem4; int func4(); class EE : private CC { int mem4; int func4(); class FF : EE { : int mem5; int func5(); Accessibility 13

14 Accessibility 14

15 Abstract Class (2) Accessibility 15

16 References [1] W Savitch, Absolute C++ [2] P.S. Wang, Standard C++ with objected-oriented programming [3]