1. 1. Waite Group's Object-Oriented Programming in C++, Third Edition (Publisher: Macmillan Computer Publishing) Author(s): Robert Lafore ISBN: 157169160x Publication Date: 11/25/98 Bottom of Form Previous Table of Contents Next Preface The major changes to this Third Edition are concerned with Standard C++ and object-oriented design. In addition, the book is no longer geared exclusively to Borland C++ compilers. Standard C++, finalized in the fall of 1997, introduced many new features to C++. Some of these features, such as templates and exceptions, had already been adopted by compiler manufacturers. However, the Standard Template Library (STL) has only recently been included in compilers. This book adds a chapter on the STL. Weve also introduced other features from Standard C++, including new header files, the string class, new-style casts, namespaces, and so on. The design of object-oriented programs has received increasing emphasis in recent years, so weve added a chapter on object-oriented design. The advent of Standard C++ means that, at least to a greater extent than before, all compilers should treat source code in the same way. Accordingly, weve modified our emphasis on Borland compilers, and now focus on code that should work with any Standard C++ compiler. Of course, the reality seldom matches the ideal, so so the programs in this book have been tested with both Microsoft and Borland compilers, and modified when necessary to work with both of them. Previous Table of Contents Next Page 1 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
2. 2. Waite Group's Object-Oriented Programming in C++, Third Edition (Publisher: Macmillan Computer Publishing) Author(s): Robert Lafore ISBN: 157169160x Publication Date: 11/25/98 Bottom of Form Previous Table of Contents Next About the Author Robert Lafore has been writing books about computer programming since 1982. His best-selling titles include Assembly Language Programming for the IBM PC, C Programming Using Turbo C++, C++ Interactive Course, and Data Structures and Algorithms in Java. Mr. Lafore holds degrees in mathematics and electrical engineering, and has been active in programming since the days of the PDP-5, when 4K of main memory was considered luxurious. His interests include hiking, windsurfing, and recreational mathematics. Acknowledgments to the Third Edition Id like to thank the entire team at Macmillan Computer Publishing. In particular, Tracy Dunkelberger ably spearheaded the entire project and exhibited great patience with what turned out to be a lengthy schedule. Jeff Durham handled the myriad details involved in interfacing between me and the editors with skill and good humor. Andrei Kossorouko lent his expertise in C++ to ensure that I didnt make this edition worse instead of better. Acknowledgments to the Second Edition My thanks to the following professorsusers of this book as a text at their respective colleges and universitiesfor their help in planning the second edition: Dave Bridges, Frank Cioch, Jack Davidson, Terrence Fries, Jimmie Hattemer, Jack Van Luik, Kieran Mathieson, Bill McCarty, Anita Millspaugh, Ian Moraes, Jorge Prendes, Steve Silva, and Edward Wright. I would like to thank the many readers of the first edition who wrote in with corrections and suggestions, many of which were invaluable. At Waite Group Press, Joanne Miller has ably ridden herd on my errant scheduling and filled in as academic liaison, and Scott Calamar, as always, has made sure that everyone knew what they were doing. Deirdre Greene provided an uncannily sharp eye as copy editor. Thanks, too, to Mike Radtke and Harry Henderson for their expert technical reviews. Special thanks to Edward Wright, of Western Oregon State College, for reviewing and experimenting with the new exercises. Acknowledgments to the First Edition My primary thanks go to Mitch Waite, who poured over every inch of the manuscript with painstaking attention to detail and made a semi-infinite number of helpful suggestions. Bill McCarty of Azusa Pacific University reviewed the content of the manuscript and its suitability for classroom use, suggested many excellent improvements, and attempted to correct my dyslexic spelling. Page 2 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
3. 3. George Leach ran all the programs, and, to our horror, found several that didnt perform correctly in certain circumstances. I trust these problems have all been fixed; if not, the fault is entirely mine. Scott Calamar of The Waite Group dealt with the myriad organizational aspects of writing and producing this book. His competence and unfailing good humor were an important ingredient in its completion. I would also like to thank Nan Borreson of Borland for supplying the latest releases of the software (among other useful tidbits), Harry Henderson for reviewing the exercises, Louise Orlando of The Waite Group for ably shepherding the book through production, Merrill Peterson of Matrix Productions for coordinating the most trouble-free production run Ive ever been involved with, Juan Vargas for the innovative design, and Frances Hasegawa for her uncanny ability to decipher my sketches and produce beautiful and effective art. Dedication This book is dedicated to GGL another inodomitable spirit.222 Tell Us What You Think! As the reader of this book, you are our most important critic and commentator. We value your opinion and want to know what were doing right, what we could do better, what areas youd like to see us publish in, and any other words of wisdom youre willing to pass our way. As the Executive Editor for the Advanced Programming and Distributed Architectures team at Macmillan Computer Publishing, I welcome your comments. You can fax, email, or write me directly to let me know what you did or didnt like about this bookas well as what we can do to make our books stronger. Please note that I cannot help you with technical problems related to the topic of this book, and that due to the high volume of mail I receive, I might not be able to reply to every message. When you write, please be sure to include this books title and author as well as your name and phone or fax number. I will carefully review your comments and share them with the author and editors who worked on the book. Fax: 317-817-7070 Email: programming@mcp.com Mail: Tracy Dunkelberger Executive Editor Advanced Programming and Distributed Architectures Macmillan Computer Publishing 201 West 103rd Street Indianapolis, IN 46290 USA Previous Table of Contents Next Page 3 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
4. 4. Waite Group's Object-Oriented Programming in C++, Third Edition (Publisher: Macmillan Computer Publishing) Author(s): Robert Lafore ISBN: 157169160x Publication Date: 11/25/98 Bottom of Form Previous Table of Contents Next APPENDIX A ASCII Chart Table A.1 IBM Character Codes DEC HEX Symbol Key Use in C 0 00 (NULL) Ctrl 2 1 01 A Ctr A 2 02 B Ctrl B 3 03 C Ctrl C 4 04 D Ctrl B 5 05 E Ctrl E 6 06 F Ctrl F 7 07 G Ctrl G Beep 8 08 H Backspace Backspace 9 09 I Tab Tab 10 0A J Ctrl J Linefeed (new line) 11 0B K Ctrl K Vertical Tab 12 0C L Ctrl L Form Feed 13 0D M Enter Carriage Return 14 0E N Ctrl N 15 0F O Ctrl O 16 10 P Ctrl P 17 11 Q Ctrl Q 18 12 R Ctrl R 19 13 S Ctrl S 20 14 T Ctrl T 21 15 U Ctrl U 22 16 _ Ctrl V 23 17 W Ctrl W 24 18 X Ctrl X 25 19 Y Ctrl Y 26 1A Z Ctrl Z 27 1B a Escape Page 4 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
5. 5. 28 1C b Ctrl29 1D c Ctrl ] 30 1E d Ctrl 6 31 1F e Ctrl 32 20 SPACE BAR 33 21 ! ! 34 22 35 23 # # 36 24 $ $ 37 25 % % 38 26 & & 39 27 40 28 ( ( 41 29 ) ) 42 2A * * 43 2B + + 44 2C , , 45 2D 46 2E . . 47 2F / / 48 30 0 0 49 31 1 1 50 32 2 2 51 33 3 3 52 34 4 4 53 35 5 5 54 36 6 6 55 37 7 7 56 38 8 8 57 39 9 9 58 3A : : 59 3B ; ; 60 3C < < 61 3D = = 62 3E > > 63 3F ? ? 64 40 @ @ 65 41 A A 66 42 B B 67 43 C C Page 5 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
6. 6. 68 44 D D 69 45 E E 70 46 F F 71 47 G G 72 48 H H 73 49 I I 74 4A J J 75 4B K K 76 4C L L 77 4D M M 78 4E N N 79 4F O O 80 50 P P 81 51 Q Q 82 52 R R 83 53 S S 84 54 T T 85 55 U U 86 56 V V 87 57 W W 88 58 X X 89 59 Y Y 90 5A Z Z 91 5B [ [ 92 5C 93 5D ] ] 94 5E ^ ^ 95 5F _ _ 96 60 ' ' 97 61 a a 98 62 b b 99 63 c c 100 64 d d 101 65 e e 102 66 f f 103 67 g g 104 68 h h 105 69 i i 106 6A j j 107 6B k k Page 6 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
7. 7. 108 6C l l 109 6D m m 110 6E n n 111 6F o o 112 70 p p 113 71 q q 114 72 r r 115 73 s s 116 74 t t 117 75 u u 118 76 v v 119 77 w w 120 78 x x 121 79 y y 122 7A z z 123 7B { { 124 7C | | 125 7D } } 126 7E ~ ~ 127 7F f Ctrl 128 80 Alt 128 129 81 Alt 129 130 82 Alt 130 131 83 Alt 131 132 84 Alt 132 133 85 Alt 133 134 86 Alt 134 135 87 Alt 135 136 88 Alt 136 137 89 Alt 137 138 8A Alt 138 139 8B Alt 139 140 8C Alt 140 141 8D Alt 141 142 8E Alt 142 143 8F Alt 143 144 90 Alt 144 145 91 Alt 145 146 92 Alt 146 147 93 Alt 147 Page 7 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
8. 8. 148 94 Alt 148 149 95 Alt 149 150 96 Alt 150 151 97 Alt 151 152 98 Alt 152 153 99 Alt 153 154 9A Alt 154 155 9B Alt 155 156 9C Alt156 157 9D Alt157 158 9E Alt158 159 9F Alt159 160 A0 Alt160 161 A1 Alt161 162 A2 Alt162 163 A3 Alt163 164 A4 Alt164 165 A5 Alt165 166 A6 a Alt166 167 A7 o Alt167 168 A8 Alt168 169 A9 Alt169 170 AA Alt170 171 AB ' Alt 171 172 AC .. Alt 172 173 AD Alt 173 174 AE Alt 174 175 AF Alt 175 176 B0 Alt 176 177 B1 Alt 177 178 B2 Alt 178 179 B3 Alt 179 180 B4 Alt 180 181 B5 Alt 181 182 B6 Alt 182 183 B7 Alt 183 184 B8 Alt 184 185 B9 Alt 185 186 BA Alt 186 187 BB a Alt 187 Page 8 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
9. 9. 188 BC o Alt 188 189 BD Alt 189 190 BE Alt 190 191 BF Alt 191 192 C0 Alt 192 193 C1 Alt 193 194 C2 Alt 194 195 C3 Alt 195 196 C4 Alt 196 197 C5 Alt 197 198 C6 Alt 198 199 C7 Alt 199 200 C8 Alt 200 201 C9 ... Alt 201 202 CA g Alt 202 203 CB Alt 203 204 CC Alt 204 205 CD Alt 205 206 CE Alt 206 207 CF Alt 207 208 D0 Alt 208 209 D1 Alt 209 210 D2 " Alt 210 211 D3 " Alt 211 212 D4 Alt 212 213 D5 " Alt 213 214 D6 Alt 214 215 D7 Alt 215 216 D8 Alt 216 217 D9 Alt 217 218 DA / Alt 218 219 DB Alt 219 220 DC < Alt 220 221 DD > Alt 221 222 DE fi Alt 222 223 DF fl Alt 223 224 E0 Alt 224 225 E1 Alt 225 226 E2 Alt 226 227 E3 Alt 227 Page 9 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
10. 10. 228 E4 Alt 228 229 E5 Alt 229 230 E6 Alt 230 231 E7 Alt 231 232 E8 Alt 232 233 E9 Alt 233 234 EA Alt 234 235 EB Alt 235 236 EC Alt 236 237 ED Alt 237 238 EE Alt 238 239 EF Alt 239 240 F0 Alt 240 241 F1 + Alt 241 242 F2 Alt 242 243 F3 Alt 243 244 F4 Alt 244 245 F5 1 Alt 245 246 F6 Alt 246 247 F7 Alt 247 248 F8 Alt 248 249 F9 Alt 249 250 FA . Alt 250 251 FB Alt 251 252 FC Alt 252 253 FD Alt 253 254 FE < Alt 254 255 FF (blank) Alt 255 Those key sequences consisting of Ctrl are typed by pressing the CTRL key, and while it is being held down, pressing the key indicated. These sequences are based on those defined for PC Personal Computer series keyboards. The key sequences may be defined differently on other keyboards. IBM Extended ASCII characters can be displayed by pressing the Alt key and then typing the decimal code of the character on the keypad. Previous Table of Contents Next Page 10 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
11. 11. Waite Group's Object-Oriented Programming in C++, Third Edition (Publisher: Macmillan Computer Publishing) Author(s): Robert Lafore ISBN: 157169160x Publication Date: 11/25/98 Bottom of Form Previous Table of Contents Next APPENDIX B STANDARD C++ KEYWORDS Keywords implement specific C++ language features. They cannot be used as names for variables or other user-defined program elements. Many of the keywords are common to both C and C++, while others are specific to C++. Some compilers may support additional keywords, which usually begin with one or two underscores, as in _cdecl or __int16. A asm auto B bool break C case catch char class const const_cast continue D default delete do double dynamic_cast E else enum explicit export extern F false Page 11 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
12. 12. float for friend G goto I if inline int L long M main mutable N namespace new O operator P private protected public R register reinterpret_cast return S short signed sizeof static static_cast struct switch T template this throw true try typedef Page 12 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
13. 13. typeid typename U union unsigned using V virtual void volatile W wchar_t while Previous Table of Contents Next Page 13 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
14. 14. Waite Group's Object-Oriented Programming in C++, Third Edition (Publisher: Macmillan Computer Publishing) Author(s): Robert Lafore ISBN: 157169160x Publication Date: 11/25/98 Bottom of Form Previous Table of Contents Next APPENDIX C MICROSOFT VISUAL C++ This appendix tells you how to use Microsoft Visual C++ to create console-mode applications, which are the kind of applications used in this book. This discussion is based on Visual C++ version 5.0. The present version of Visual C++ has good (although not perfect) adherence to Standard C++. It comes in various versions, including a student version for under $100. Well assume that Visual C++ is installed in your system, and that you know how to start it by using the Windows Start button and navigating to the appropriate menu item: Microsoft Visual C++. Youll want to make sure you can see file extensions (like .CPP) when operating MVC++. In Windows Explorer, make sure that the option Hide MS-DOS File Extensions for File Types That are Registered is not checked. Screen Elements When you start Microsoft Visual C++ youll see that the resulting application is actually called Microsoft Developer Studio. The studio can work with other languages besides C++, but we wont worry about that here. The Developer Studio window is initially divided into three parts. On the left is the View Pane. This has three tabs, for ClassView, FileView, and InfoView. Once you have a project going, the ClassView tab will show you the class hierarchy of your program, and FileView will show you the files used in the project. InfoView allows you to navigate through the documentation and help file structure. Click the plus signs to expand the hierarchies, then double-click the document you want to read. The largest part of the screen usually holds a document window. It can be used for various purposes, including displaying your source files. It can also display the contents of help files. At the bottom of the screen is a long window with more tabs: Build, Debug, and so on. This will display messages when you perform operations such as compiling your program. Single-File Programs Its easy to build and execute a single-file console program using Microsoft Visual C++. There are two possibilities: the file already exists or the file needs to be written. In either case you should begin by making sure that no project is currently open. (Well discuss projects in a moment.) Click the File menu. If the Close Workspace item is active (not grayed) click it to close the current workspace. Building an Existing File Page 14 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
15. 15. If the .CPP source file already exists, as it does for the example programs in this book, select Open from the File menu. (Note that this is not the same as Open Workspace.) Use the Open dialog box to navigate to the appropriate file, select it, and click the Open button. The file will appear in the document window. (If youre compiling an example program that uses Console Graphics Lite, such as the CIRCSTRC program in Chapter 5, Functions, or the CIRCLES program in Chapter 6, Objects and Classes, turn to the section Building Console Graphics Lite Programs.) To compile and link this file, select Build from the Build menu. A dialog box will appear asking if you want to create a Default Project Workspace. Click Yes. The file will be compiled and linked with any necessary library files. To run the program, select Execute from the Project menu. If all goes well, a console window will appear with the programs output displayed in it. When the program terminates, youll see the phrase Press any key to continue. The compiler arranges for this to be inserted following the termination of any program. It keeps the console display on the screen long enough to see the programs output. You can also run programs directly from MS-DOS. In Windows 95 and 98, you can obtain a box for MS-DOS by clicking the Start button, selecting Programs and then the MS-DOS Prompt item. In the resulting window youll see whats called the C-prompt: the letter C, usually followed by the name of the current directory. You can navigate from one directory to another by typing cd (for Change Directory) and the name of the new directory. To execute a program, including any of the examples from this book, make sure youre in the same directory as the appropriate .EXE file, and type the name of the program (with no extension). You can find out more about MS-DOS using the Windows help system. Writing a New File To start writing your own .CPP file, select New from the File menu and click the Files tab. Select C++ Source File, and click OK. A blank document window will appear. Type in your program. Save the new file by selecting Save As from the File menu, navigating to the correct directory, and typing the file name with the .CPP extension (such as myProg.cpp). As before, select Build from the Build menu and click Yes to the default workspace question. Your program will be compiled and linked. If there are errors, they will appear in the Build window at the bottom of the screen. (You may need to click the Build tab to make this window appear.) If you double-click the error line, an arrow will appear next to the line containing the error in the source file. Also, if you position the cursor on the error number in the Build window (such as C2143) and press the F1 key, an explanation of the error will appear in the document window. You can correct the errors and repeat the build process until the message reads 0 error(s), 0 warning(s). To execute the program, select Execute from the Build menu. Before working on a new program, dont forget to select Close Workspace from the File menu. This ensures that you begin with a clean workspace. To open a program youve already built, select Open Workspace from File menu, navigate to the right directory, and double-click the file with the appropriate name and the .DSW extension. Run-Time Type Information (RTTI) A few programs, such as EMPL_IO.CPP in Chapter 12, Streams and Files, use RTTI. With Microsoft Visual C++ you need to enable a compiler option to make this feature work. Select Settings from the Project menu and click the C/C++ tab. From the Category list box, select C++ Language. Click the checkbox named Enable Run-Time Type Information. This will avoid various compiler and linker errors, some of which are misleading. Page 15 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
16. 16. Multifile Programs Weve shown the quick and dirty approach to building programs. This approach works with one-file programs. When projects have more than one file things become slightly more complicated. Well start by reviewing whats meant by the terms workspace and project. Projects and Workspaces Visual C++ uses a concept called a workspace, which is one level of abstraction higher than a project. A workspace can contain many projects. It consists of a directory and several configuration files. Within it, each project can have its own directory, or the files for all the projects can simply reside in the workspace directory. Conceptually its probably easiest, at least for the small programs in this book, to assume that every project has its own separate workspace. Thats what well assume in this discussion. A project corresponds to an application (program) that youre developing. It consists of all the files needed to create that application as well as information about how these files are to be combined. The result of building a project is usually a single .EXE file that a user can execute. (Other results are possible, such as .DLL files.) Source Files Already Exist Lets assume that the files you want to include in a new project already exist, and that they are in a particular directory. Select New from the File menu, and click the Projects tab in the New dialog box. Select Win32 Console Application from the list. First, in the Location box, type the path to the directory, but do not include the directory name itself. Next, type the name of the directory containing the files in the Project Name box. (By clicking the button to the right of the Location field you can navigate to the appropriate directory, but make sure to delete the directory name itself from the location field.) Make sure the Create New Workspace box is checked, and click OK. For example, if the files are in C:BookCh13Elev, then you would first type C:BookCh13 in the Location field and then Elev in the Project Name field. When you type the project name, its automatically added to the location. (If it was there already it would be added again, resulting in a location of C:BookCh13ElevElev , which is not what you want.) At this point various project-oriented files, with extension .DSP, .DSW, and so forth, have been added to the directory. Now you need to add your source files to the project. This includes both .CPP and .H files. Select Add To Project from the Project menu, click Files, select the files you want to add, and click OK. You can review the files youve selected by clicking the FileView tab and then the plus sign for the project. You can also see the class structure, complete with member functions, by clicking the ClassView tab. To open a file so you can see it and modify it, select Open from the File menu and select the file. Sometimes a file (such as the msoftCon.h file necessary for console graphics programs) is not in the same directory as the other source files for your program. You can nevertheless add it to your project in the same way that you add other files. Select Add To Project from the Project menu, select Files, and then navigate to the file you want (or type in the complete pathname). Saving, Closing, and Opening Projects Page 16 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
17. 17. To save the project, select Save Workspace. To close the project, select Close Workspace. (Answer Yes to the query Close All Document Windows.) To open an existing project, select Open Workspace from the file menu, navigate to the proper directory, select the .DSW file, and click Open. Compiling and Linking As with one-file programs, the easiest way to compile, link, and run a multifile program is to select Execute from the Build menu. You can compile and link your project without running it by selecting Build from the Build menu. Building Console Graphics Lite Programs Building programs that use the Console Graphics Lite functions (described in Appendix E, Console Graphics Lite) requires some steps in addition to those needed for ordinary example programs. Programs that use these functions should include the line #include msoftcon.h. Open the source file for the program as described earlier. Select Build from the Build menu. Answer Yes when asked if you want to create a default project workspace. A project will be created, but the compiler will complain it cant find MSOFTCON.H. To tell it where to find this file, select Options from the Tools menu. Click on the Directories tab. Select Include Files from the Show Directories For list. On the bottom line of the Directories list, type the complete pathname of the directory where MSOFTCON.H is stored. (This directory should be called MSOFTCON.) Click on OK. Now try building your file again. Now the compiler can find the header file, but there will be numerous linker errors because the linker doesnt know where to find the code for the graphics functions. This code is in MSOFTCON.CPP. Select Add To Project from the Project menu; then select Files. In the resulting dialog box (called Insert Files into Project), navigate to the MSOFTCON directory. Select the MSOFTCON.CPP file. Click OK. Now your program should compile and link correctly. Select Execute from the Build menu to see it run. Debugging In Chapter 3, Loops and Decisions, we suggest using the debugger to provide an insight into how loops work. Heres how to do that with Microsoft Visual C++. These same steps can help you debug your program if it behaves incorrectly. Well be discussing onefile programs here, but the same approach applies, with appropriate variations, to larger multifile programs. Start by building your program as you normally would. Fix any compiler and linker errors. Make sure your program listing is displayed in the Edit window. Single Stepping To start the debugger, simply press the F10 key. Youll see a yellow arrow appear in the margin of the listing, pointing to the opening brace following main. If you want to start somewhere other than the beginning of the program, position the cursor on the line where you want to start debugging. Then, from the Build menu, select Start Debug, and then Run to Cursor. The yellow arrow will appear next to the statement selected. Now press the F10 key. This causes the debugger to step to the next executable statement. The yellow arrow will show where you are. Each press of F10 moves it to the next statement. If youre in a loop, you Page 17 ABC Amber CHM Converter Trial version, http://www.processtext.com/abcchm.html
18. 18. ll see the yellow arrow move down through the statements in the loop and then jump back to the top of the loop. Watching Variables Youll see a Watch window in the bottom right corner of your screen. To observe the values of variables change as you step through the program, youll need to place these variables names in this Watch window. To do this, rightclick a variable name in the source code. A popup menu will appear. Select QuickWatch from this menu. In the resulting QuickWatch dialog box, click Add Watch. The variable and its current value will appear in the Watch window. If a variable is out of scope, such as before its been defined, the Watch window will show an error message instead of a value next to the variable name. Stepping Into Functions If your program uses functions, you can step into them (singlestep through the statements within the function) by using the F11 key. By contrast, the F10 key steps over function calls (treats them as a single statement). If you use F11 to trace into library routines like cout