Learn C++ Programming Language

1

• The C Language

2
Overview of C

• Bjarne Stroupstrup, the languages creator
• C was designed to provide Simulas facilities
  for program organization together with Cs
  efficiency and flexibility for systems
  programming.
• Modern C and C are siblings

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

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.

6
A Simple C Program

• include ltcstdlibgt
• include ltiostreamgt
• using namespace std
• int main ( )
• intx, y
• cout ltlt Please enter two numbers
• cin gtgt x gtgt y
• int sum x y
• cout ltlt Their sum is ltlt sum ltlt endl
• return EXIT_SUCCESS

7
The include Directive

• The first two lines
• include ltiostreamgt
• include ltcstdlibgt
• 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.

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 stdcin
• using stdcout
• using stdstring
• using stdgetline

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

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).

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'.

12
Operators

• Bitwise Operators
• (complement)
• (bitwise and)
• (bitwise exclusive or)
• (bitwise or)
• ltlt (shift left)
• gtgt (shift right)
• Assignment Operators
• , -, , /, , , , , ltlt, gtgt
• Other Operators
• (scope resolution)
• ? (conditional expression)
• stream ltlt var
• stream gtgt exp

13
Increment and Decrement

• Prefix
• x
• x is replaced by x1, and the value is x1
• --x
• x is replaced by x-1, and the value is x-1
• Postfix
• x
• x is replaced by x1, but the value is x
• x--
• x is replaced by x-1, but the value is x

14
Object-Oriented Concept (C)

• Objects of the program interact by sending
  messages to each other

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

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

17
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

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

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

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 destructor for 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

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

22
Constructor and Destructor

• PointPoint(const int x, const int y) _x(x),
  _y(y)
• PointPoint(const Point from)
• _x from._x
• _y from._y
• PointPoint(void)
• / nothing to do /

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)

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))

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))

26
Standard Input/Output Streams

• Stream is a sequence of characters
• Working with cin and cout
• Streams convert internal representations to
  character streams
• gtgt input operator (extractor)
• ltlt output operator (inserter)

27

• Thank You