The C++ Language Tutorial

cplusplus.com C++ Language Tutorial Written by:J uan Souli é Last revision:J une, 200 7 Available online at: http://www.cplusplus.com/doc/tutorial/ The online version is constantly revised and may contain corrections and changes The C++ Language Tutorial This document and its content is copyrightp luosf. cocpmlu s © cplusplus.com, 2008. Alvl edri.g hts reser Any redistribution or reproduction of part or all of the content in any form is prohibited other than to print a personal copy of the entire document or download it to a local hard disk, without modifying its content in any way (including, but not limited to, this copyright no ctei). You may not, except with express written permission from cplusplus.com, distribute the content of th idsocument. Nor may you transmit it or store it in any other website or other form of electronic retrieval system. 2 © cplusplus.com 2008. All rights reserved The C++ Language Tutorial Table of contents Table of contents ................................................................. ...................3 Introduction ....................................................................... ....................5 Instructions for use ...........................................................................................................5. ....................... Basics of C++ ...................................................................... ....................7 Structure of a program ..................................................................................... 7 Variables. Data Types. .................................................................................... 11 Constants ........................................................................................................................ 1.7. ...................... Operators ......................................................................... 2.1. ...................... Basic Input/Output ....................................................................................... 29 Control Structures .................................................................. ................. 34 Control Structures .............................................................................................................. ..................... 34 Functions (I) ....................................................................... 4.1. ...................... Functions (II) ...................................................................... 4.7. ...................... Compound data types .............................................................. .............. 54 Arrays ................................................................................................................................. 5.4. ................... Character Sequences .................................................................................... 60 Pointers ............................................................................ 6.3. .................... Dynamic Memory ........................................................................................ 74 Data structures.....................................................................7. ...................... 7 Other Data Types ......................................................................................... 82 Object Oriented Programming ........................................................ .............. 86 Classes (I).......................................................................... 8.6. .................... Classes (II) ......................................................................... 9..5. ................... Friendship and inheritance ............................................................................. 100 Polymorphism .......................................................................................... 107 Advanced concepts ................................................................. ............. 113 Templates........................................................................1.3. ..................... 1 Namespaces ........................................................................ .................... 120 Exceptions .......................................................................1.2.3. ..................... Type Casting ...................................................................................................................2.7. ..................... 1 3 © cplusplus.com 2008. All rights reserved The C++ Language Tutorial Preprocessor directives ................................................................................. 133 C++ Standard Library ............................................................... .............. 138 Input/Output with files ................................................................................. 138 4 © cplusplus.com 2008. All rights reserved The C++ Language Tutorial Introduction Instructions for use To whom is this tutorial directed? This tutorial is for those people who want to learn programming in C++ and do not necessarily have any previous knowledge of other programming languages. Of course any knowledge of other programming languages or any general computer skill can be useful to better understand this tutorial, although it is not essential. It is also suitable for those who need a little update on the new features the language has acquired from the latest standards. If you are familiar with the C language, you can take the first 3 parts of this tutorial as a review of concepts, since they mainly explain the C part of C++. There are slight differences in the C++ syntax for some C features, so I recommend you its reading anyway. The 4th part describes object-oriented programming. The 5th part mostly describes the new features introduced by ANSI-C++ standard. Structure of this tutorial The tutorial is divided in 6 parts and each part is divided on its turn into different sections covering a topic each one. You can access any section directly from the section index available on the left side bar, or begin the tutorial from any point and follow the links at the bottom of each section. Many sections include examples that describe the use of the newly acquired knowledge in the chapter. It is recommended to read these examples and to be able to understand each of the code lines that constitute it before passing to the next chapter. A good way to gain experience with a programming language is by modifying and adding new functionalities on your own to the example programs that you fully understand. Don't be scared to modify the examples provided with this tutorial, that's the way to learn! Compatibility Notes The ANSI-C++ standard acceptation as an international standard is relatively recent. It was first published in November 1997, and revised in 2003. Nevertheless, the C++ language exists from a long time before (1980s). Therefore there are many compilers which do not support all the new capabilities included in ANSI-C++, especially those released prior to the publication of the standard. This tutorial is thought to be followed with modern compilers that support -at least on some degree- ANSI-C++ specifications. I encourage you to get one if yours is not adapted. There are many options, both commercial and free. Compilers The examples included in this tutorial are all console programs. That means they use text to communicate with the user and to show their results. 5 © cplusplus.com 2008. All rights reserved The C++ Language Tutorial All C++ compilers support the compilation of console programs. Check the user's manual of your compiler for more info on how to compile them. 6 © cplusplus.com 2008. All rights reserved The C++ Language Tutorial Basics of C++ Structure of a program Probably the best way to start learning a programming language is by writing a program. Therefore, here is our first program: // my first program in C++ Hello World! #include using namespace std; int main () { cout << "Hello World!"; return 0; } The first panel shows the source code for our first program. The second one shows the result of the program once compiled and executed. The way to edit and compile a program depends on the compiler you are using. Depending on whether it has a Development Interface or not and on its version. Consult the compilers section and the manual or help included with your compiler if you have doubts on how to compile a C++ console program. The previous program is the typical program that programmer apprentices write for the first time, and its result is the printing on screen of the "Hello World!" sentence. It is one of the simplest programs that can be written in C++, but it already contains the fundamental components that every C++ program has. We are going to look line by line at the code we have just written: // my first program in C++ This is a comment line. All lines beginning with two slash signs (//) are considered comments and do not have any effect on the behavior of the program. The programmer can use them to include short explanations or observations within the source code itself. In this case, the line is a brief description of what our program is. #include Lines beginning with a hash sign (#) are directives for the preprocessor. They are not regular code lines with expressions but indications for the compiler's preprocessor. In this case the directive #include tells the preprocessor to include the iostream standard file. This specific file (iostream) includes the declarations of the basic standard input-output library in C++, and it is included because its functionality is going to be used later in the program. using namespace std; All the elements of the stan