Structure of C++ Program:
Chronological order of C++ program.
1. Class declaration
2. Main function program
3. Member functions definitions
4. Include header files
C++ program are stored in three files. File header in one file, Class declaration and member function in another file, and the main function program in the third file. The Class declaration and member function file is stored in server and the main function program in the client. This client-server set up will enable several clients to use the same class to work on various modules or program.
Some header files:
Some of header files in C++ are; cctye, cfloat, climits, cmath, cstdio, cstdlib, cstring,
iostream, iomanip, bitset, list, stack, queue, deque, vector, map, utility, memory, string, sstream, set, locale, limits, typeinfo, iterator, functional, etc.
A simple program: Example 1:
#include
int main( )
{cout << "My first C++ program.\n";
return 0;
}
Example 2:
#include
int main( )
{float num1, num2,sum,avg;
cout << "Enter two number with space between numbers.\n";
cin >> num1>> num2;//each variable should have separate extraction operator
sum = num1 + num2;
avg = sum/2;
//each variable should have separate inseration operator sum, avg is invalid cout << "The sum is" << sum << "\n";
cout << "The average is" << avg << "\n";
return 0;
}
These simple C++ programs it may look similar to C with small changes, without of printf and scanf in C here cout and cin are used with << and >> insertion operator. Remember when a function has a return type it should have a return value since main function has a return type of integer the function return 0 at the end of the program to indicate the end. Just like C the C++ statement must end with semicolon and it must have only one main function. Remember <<, and
>> operators are also used as bit-wise left shift and right shift operators, thus the process of using same operator for different purpose is known Operator Overloading. Operator overloading is another example for polymorphism.