Antitrust Notice. Using C++: A First Step. Overview 3/17/2011

Transcription

1 Antitrust Notice The Casualty Actuarial Society is committed to adhering strictly to the letter and spirit of the antitrust laws. Seminars conducted under the auspices of the CAS are designed solely to provide a forum for the expression of various points of view on topics described in the programs or agendas for such meetings. Under no circumstances shall CAS seminars be used as a means for competing companies or firms to reach any understanding expressed or implied that restricts competition or in any way impairs the ability of members to exercise independent business judgment regarding matters affecting competition. It is the responsibility of all seminar participants to be aware of antitrust regulations, to prevent any written or verbal discussions that appear to violate these laws, and to adhere in every respect to the CAS antitrust compliance policy. Using C++: A First Step Copyright 2011 by William P. Rudolph. 2 Overview Preliminaries Compilers IDE vs. Command Line Getting Started Downloading the compiler Developing a program Running the program Compiler errors 3 1

2 A Closer Look at C++ Types and declarations Expressions and statements Functions Namespaces Pointers Organizing the program Source Files Header Files 4 Examples Classes and Structures Standard Library More examples 5 Preliminaries 6 2

3 Compilers Visual C++ GCC (G++) MinGW CygWin Intel Comeau Computing 7 Creating a Program IDE (Integrated Development Environment) Visual Studio Eclipse Command Line Processing Compiler Editor 8 Getting Started 9 3

4 Downloading the Compiler 10 Developing a Program Preprocessing Compilation Transforming human readable source code into machine instructions. Linking Putting the various translation units together Incorporating shared libraries (e.g. dlls)

5 Contents of directory prior to compilation 13 run.bat 14 main.cpp 15 5

6 Compilation of program 16 Contents of directory after compilation 17 Running the program 18 6

7 #include <iostream> int main() std::cout<<"hello world"; Executable Size: bytes 19 Running the program 20 #include <iostream> int main() std::cout<<"hello world"; 21 7

8 Compilation Errors 22 #include <iostream> int main() std::cout<<"hello world" ; 23 Compilation Errors 24 8

9 A Closer Look at C++ 25 A name is a sequence of letters and digits used to identify user defined entities. Each name has a type associated with it. A type defines the proper use of a name or expression. 26 Type int i = 0 ; Name Operator Value 27 9

10 What is int i=1;? 28 It is a declaration and definition. 29 A declaration introduces a name into a scope and associates that name with a type. A definition is a declaration that specifies the entity to which the name refers

11 Before a name can be used it must be declared and defined. 31 Declaration/Definition int main() ++i; int main() ++i; int i=1; int main() int i=1; ++i; Incorrect Incorrect Correct 32 int is an integer type

12 Characteristics of int on a windows computer size 4 bytes min max Note: These characteristics vary by implementation. 34 int i=1; A definition is a declaration that In specifies this An case, object The the the value is entity memory is to 1. is which an that object. the holds a value. name refers. 35 Some Operations on int Description Operator add + equal == assignment = multiply and assign *= x*=y is equivalent to x=x*y 36 12

13 int a=2, b=3, c=5; a*=b+c; What does a equal? Comments in Code // this is a comment /* */ this is a comment 38 Description Pre-increment Post-increment Operator ++i i++ int i=0, j=0; j=++i; //j==1, i==1 int i=0, j=0; j=i++; //j==0, i==

14 A type defines the proper use of a name or expression. int size possible values operations 40 Other Built in Types Integer Type Floating Point Type type long long double size 8 bytes 8 bytes min e-308 max max= e+308 notes type is not in standard 15 digits mantissa 41 Other Built in Types Type Comments Boolean Type bool true/false Character Type char 1 byte 42 14

15 Examples of Declarations and Definitions int my_integer(0); int n(-5), j=1; double dbl=0.0; char c= k ; bool loop=true; 43 Scope Rules int i=4; //i==4 //i==4 ++i; //i==5 //i==5 int i=1; int i=2; Incorrect 44 Scope Rules int i=5; //i==5; //i==5 int i=5; /* i does not exist */ int i=4; //i==4 //i==4 int i=5; //i==5 //i==

16 if and if/else int i=2; if(i<20) int i=2; if(i<20) else 46 Loops int i=0; while(i<1000) ++i; for(int i=0;i<1000;++i) 47 Functions 48 16

17 A name is a sequence of letters and digits used to identify user defined entities. Each name has a type associated with it. A type defines the proper use of a name or expression. 49 Argument type int my_function ( double ) Name Return type 50 Examples of Functions int my_function(double,bool) void your_function() 51 17

18 Declaration Definition and Declaration void my_function(); void my_function() 52 void my_function() int main() my_function(); void my_function(); int main() my_function(); void my_function() 53 j is the A reference is here another and therefore another name for for an object void f() in this case, memory that int i=1; holds the value 1. int& j=i;

19 void f() int i=0; int& j=i; ++j; //i==1 //j==1 void f() int& j; int& k=1; Incorrect 55 Argument Passing Call by Value void f(int j) Call by Reference void f(int& j) 56 void f (int j) ++j; //j==1 int main() int i=0; f(i); //i==0 void f (int& j) ++j; //j==1 int main() int i=0; f(i); //i==

20 Return Values Value Reference int f() int i=1; return i; int& f() int i=1; return i; int& f(int & i) return i; 58 Overloaded Functions int my_function(double) int my_function(int) 59 Namespaces Used to express logical structure Code separated into different scopes 60 20

21 Namespace Example namespace rng int generator(int seed) double variate(int i) return rng::pareto(i); double pareto (int i) double r=generator(i); 61 Additional content will be made available by March 20, Additional Readings Just Starting Out Programming: Principals and Practice Using C++ by Bjarne Stroustrup Accelerated C++ by Andrew Koenig and Barbara Moo 63 21

22 Intermediate The C++ Programming Language by Bjarne Stroustrup The C++ Standard Library by Nicolai Josuttis Effective C++ by Scott Meyers 64 Advanced C++ Templates by David Vandevoorde and Nicolai Josuttis Exceptional C++ by Herb Sutter Modern C++ Design by Andrei Alexandrescu 65 Design Patterns by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides Generative Programming by Krzysztof Czarnecki and Ulrich Eisenecker Standard C++ IOStreams and Locales by Angelika Langer and Klaus Kreft 66 22