Learn C Programming Language

1. The C++ Language www.myassignmenthelp.net

2. Overview of ‘C++’ • Bjarne Stroupstrup, the language’s creator • C++ was designed to provide Simula’s facilities for program organization together with C’s efficiency and flexibility for systems programming. • Modern C and C++ are siblings www.myassignmenthelp.net

3. Outline • C++ basic features • Programming paradigm and statement syntax • Class definitions • Data members, methods, constructor, destructor • Pointers, arrays, and strings • Parameter passing in functions • Templates • Friend • Operator overloading • I/O streams • An example on file copy • Makefile

4. C++ Features • Classes • User-defined types • Operator overloading • Attach different meaning to expressions such as a + b • References • Pass-by-reference function arguments • Virtual Functions • Dispatched depending on type at run time • Templates • Macro-like polymorphism for containers (e.g., arrays) • Exceptions www.myassignmenthelp.net

5. Compiling and Linking • A C++ program consists of one or more source files. • Source files contain function and class declarations and definitions. • Files that contain only declarations are incorporated into the source files that need them when they are compiled. • Thus they are called include files. • Files that contain definitions are translated by the compiler into an intermediate form called object files. • One or more object files are combined with to form the executable file by the linker. www.myassignmenthelp.net

6. A Simple C++ Program #include <cstdlib> #include <iostream> using namespace std; int main ( ) { intx, y; cout << “Please enter two numbers:”; cin >> x >> y; int sum = x + y; cout << “Their sum is “ << sum << endl; return EXIT_SUCCESS; } www.myassignmenthelp.net

7. The #include Directive • The first two lines: #include <iostream> #include <cstdlib> incorporate the declarations of the iostream and cstdlib libraries into the source code. • If your program is going to use a member of the standard library, the appropriate header file must be included at the beginning of the source code file. www.myassignmenthelp.net

8. The using Statement • The line using namespace std; tells the compiler to make all names in the predefined namespace std available. • The C++ standard library is defined within this namespace. • Incorporating the statement using namespace std; is an easy way to get access to the standard library. • But, it can lead to complications in larger programs. • This is done with individual using declarations. using std::cin; using std::cout; using std::string; using std::getline; www.myassignmenthelp.net

9. Compiling and Executing • The command to compile is dependent upon the compiler and operating system. • For the gcc compiler (popular on Linux) the command would be: • g++ -o HelloWorld HelloWorld.cpp • For the Microsoft compiler the command would be: • cl /EHsc HelloWorld.cpp • To execute the program you would then issue the command • HelloWorld www.myassignmenthelp.net

10. C++ Data Type • Basic Java types such as int, double, char have C++ counterparts of the same name, but there are a few differences: • Boolean is bool in C++. In C++, 0 means false and anything else means true. • C++ has a string class (use string library) and character arrays (but they behave differently). www.myassignmenthelp.net

11. Constants • Numeric Constants: • 1234 is an int • 1234U or 1234u is an unsigned int • 1234L or 1234l is a long • 1234UL or 1234ul is an unsigned long • 1.234 is a double • 1.234F or 1.234f is a float • 1.234L or 1.234l is a long double. • Character Constants: • The form 'c' is a character constant. • The form '\xhh' is a character constant, where hh is a hexadecimal digit, and hh is between 00 and 7F. • The form '\x' where \x is one of the following is a character constant. • String Constants: • The form "sequence of characters“ where sequence of characters does not include ‘"’ is called a string constant. • Note escape sequences may appear in the sequence of characters. • String constants are stored in the computer as arrays of characters followed by a '\0'. www.myassignmenthelp.net

12. Operators • Bitwise Operators • ~ (complement) • & (bitwise and) • ^ (bitwise exclusive or) • | (bitwise or) • << (shift left) • >> (shift right) • Assignment Operators • +=, -=, *=, /=, %=, &=, |=, ^=, <<=, >>= • Other Operators • :: (scope resolution) • ?: (conditional expression) • stream << var • stream >> exp www.myassignmenthelp.net

13. Increment and Decrement • Prefix: • ++x • x is replaced by x+1, and the value is x+1 • --x • x is replaced by x-1, and the value is x-1 • Postfix: • x++ • x is replaced by x+1, but the value is x • x-- • x is replaced by x-1, but the value is x www.myassignmenthelp.net

14. Object-Oriented Concept (C++) • Objects of the program interact by sending messages to each other www.myassignmenthelp.net

15. Basic C++ • Inherit all C syntax • Primitive data types • Supported data types: int, long, short, float, double, char, bool, and enum • The size of data types is platform-dependent • Basic expression syntax • Defining the usual arithmetic and logical operations such as +, -, /, %, *, &&, !, and || • Defining bit-wise operations, such as &, |, and ~ • Basic statement syntax • If-else, for, while, and do-while www.myassignmenthelp.net

16. Basic C++ (cont) • Add a new comment mark • // For 1 line comment • /*… */ for a group of line comment • New data type • Reference data type “&”. Much likes pointer int ix; /* ix is "real" variable */ int & rx = ix; /* rx is "alias" for ix */ ix = 1; /* also rx == 1 */ rx = 2; /* also ix == 2 */ • const support for constant declaration, just likes C www.myassignmenthelp.net

17. Initializer list: used to initialize the data members directly. Avoid implicit type conversion Member functions Indicates that the member’s invocation does not change any of the data members. Data member(s) Class Definitions • A C++ class consists of data members and methods (member functions). class IntCell { public: explicit IntCell( int initialValue = 0 ) : storedValue( initialValue ) {} int read( ) const { return storedValue;} void write( int x ) { storedValue = x; } private: int storedValue; } www.myassignmenthelp.net

18. Information Hiding in C++ • Two labels: public and private • Determine visibility of class members • A member that is public may be accessed by any method in any class • A member that is private may only be accessed by methods in its class • Information hiding • Data members are declared private, thus restricting access to internal details of the class • Methods intended for general use are made public www.myassignmenthelp.net

19. Constructors • A constructor is a special method that describes how an instance of the class (called object) is constructed • Whenever an instance of the class is created, its constructor is called. • C++ provides a default constructor for each class, which is a constructor with no parameters. But, one can define multiple constructors for the same class, and may even redefine the default constructor www.myassignmenthelp.net

20. Destructor • A destructor is called when an object is deleted either implicitly, or explicitly (using the delete operation) • The destructor is called whenever an object goes out of scope or is subjected to a delete. • Typically, the destructor is used to free up any resources that were allocated during the use of the object • C++ provides a default destructorfor each class • The default simply applies the destructor on each data member. But we can redefine the destructor of a class. A C++ class can have only one destructor. • One can redefine the destructor of a class. • A C++ class can have only one destructor www.myassignmenthelp.net

21. Constructor and Destructor class Point { private : int _x, _y; public: Point() { _x = _y = 0; } Point(const int x, const int y); Point(const Point &from); ~Point() {void} void setX(const int val); void setY(const int val); int getX() { return _x; } int getY() { return _y; } }; www.myassignmenthelp.net

22. Constructor and Destructor Point::Point(const int x, const int y) : _x(x), _y(y) { } Point::Point(const Point &from) { _x = from._x; _y = from._y; } Point::~Point(void) { /* nothing to do */ } www.myassignmenthelp.net

23. C++ Operator Overloading class Complex { ... public: ... Complex operator +(const Complex &op) { double real = _real + op._real, imag = _imag + op._imag; return(Complex(real, imag)); } ... }; In this case, we have made operator + a member of class Complex. An expression of the form c = a + b; is translated into a method call c = a.operator +(a, b); www.myassignmenthelp.net

24. Operator Overloading • The overloaded operator may not be a member of a class: It can rather defined outside the class as a normal overloaded function. For example, we could define operator + in this way: class Complex { ... public: ... double real() { return _real; } double imag() { return _imag; } // No need to define operator here! }; Complex operator +(Complex &op1, Complex &op2) { double real = op1.real() + op2.real(), imag = op1.imag() + op2.imag(); return(Complex(real, imag)); } www.myassignmenthelp.net

25. Friend • We can define functions or classes to be friends of a class to allow them direct access to its private data members class Complex { ... public: ... friend Complex operator +( const Complex &, const Complex & ); }; Complex operator +(const Complex &op1, const Complex &op2) { double real = op1._real + op2._real, imag = op1._imag + op2._imag; return(Complex(real, imag)); } www.myassignmenthelp.net

26. Standard Input/Output Streams • Stream is a sequence of characters • Working with cinand cout • Streams convert internal representations to character streams • >> input operator (extractor) • << output operator (inserter) www.myassignmenthelp.net

27. Thank You www.myassignmenthelp.net