1. Objects
   1. cin
      Standard input of class istream.
   2. cout
      Standard output of class ostream.
   3. cerr and clog
      Standard error output of class ostream.

2. Overloaded Operators
   1. <<
      Shift left is overload and called the stream insertion operator. This operator was chosen because it associates left to right, low order of precedence and just the way it look denoting the flow of data. Which means that statements like:

      	int i=47;
      	cout << i << " " << i + 3 << endl;
       
      Gives the correct output of:
      47 50
      

      This is accomplished thru the use of multiple overloaded operator definitions.

      There are defined manipulators for cout like:

      • endl -print an end of line the same as sending '\n' to cout.
      • flush - flush the output stream buffer.
   2. >>
      The shift right has been overloaded for the istream class and called the stream extractor.

3. Common manipulators and member functions to use these include <iomanip>.

   manipulator	Member function	Description
   dec	setf(ios::dec)	Set radix to 10
   hex	setf(ios::hex)	Set radix to 16
   oct	setf(ios::oct)	Set radix to 8
   setfill(c)	fill(c)	Set the fill character to c.
   setprecision(n)	precision(n)	Set display precsion to n
   setw(n)	width(n)	Set output field width to n.
   setiosflags(p)	setf(p)	Turn on IOS icontrol bits
   resetiosflags(p)	unsetf(p)	Turn off IOS control bits

4. Format state flag bits

   IOS::Flag	Description
   skipws	Skip whitespace characters on an input stream
   left	Left justify ouput
   right	Right justify the output
   internal	Left justify the sign, right justify the number
   dec	Display the number in base 10
   oct	Display the number in base 8
   hex	Display the number in base 16
   showbase	Specify base ahead of the number
   showpoint	Display floating point numbers with a decimal point
   uppercase	Use upper case in displaying numbers
   showpos	Show positive or negative signs
   scientific	Output floating point in scientific notation
   fixed	Specify the number of output to right of decimal point

5. Examples

   1. ---

      //
      //
      //
      #include <iostream>
      #include <iomanip>
      using namespace std;
      void main()
      {
          long ioflags;
          ioflags=cout.flags();
      
          int i=47;
          cout << "Integer " << i << endl;
      
          char a='a';
          cout << "Character output " << a << endl;
      
          float f=3.14159;
          cout << "Floating Point " << f << endl;
          
          cout << "Integer in hex  "  << hex << i << endl;
          cout << "Integer in Octal " << oct << i << endl;
          cout << dec;
          
          cout << "Integer in width " << setw(5) << i << endl;
          cout << "Integer in width with fill " << setfill('-') << setw(5) << i << endl;
          
          cout.flags(ioflags);
          cout.setf(ios::left);
          cout << "Justify left " << setw(5) << i << endl;
          
          cout.flags(ioflags);
          cout.fill('-');
          cout.setf(ios::right);
          cout << "Justify Right " << setw(5) << i << endl;
          
          i=-47;
          cout.fill(' ');
          cout.flags(ioflags);
          cout.setf(ios::internal);
          cout << "Internal " << setw(5) << i << endl;
          }
      

      ---

      Integer 47
      Character output a
      Floating Point 3.14159
      Integer in hex  2f
      Integer in Octal 57
      Integer in width    47
      Integer in width with fill ---47
      Justify left 47---
      Justify Right ---47
      Internal   -47
      

   2. ---

      #include <iomanip>
      #include <iostream>
      using namespace std;
      main()
      {
        char a='a';
        int  i=34,j=-34;
        float f=3.14159;
        
        cout << a << endl;
        cout << (int)a << endl;
        cout << i << " " << j << endl;
        cout << (unsigned)i << " " << (unsigned)j << endl;
        cout << oct << i << endl;
        cout << hex << i << endl;
        cout << dec;
      
        cout << f << endl;
      
        cout << setw(3) << i << " " << setw(3) << j << endl;
        cout << setiosflags( ios:: showpoint | ios::fixed);
        cout << setw(6) << setprecision(2) << f << endl;
      
         i=8;
         j=3;
         cout << setw(i) << setprecision(j) << f << endl;
        return(0);
      }
      

      ---

      a
      97
      34 -34
      34 4294967262
      42
      22
      3.14159
       34 -34
        3.14
         3.142
      

x = 1 + j/m

s = r [ (x^mn-1)/ p(x^m/p-1)]

Where s = eventual cash value 
r = payment per year 
p = installments per year 
n = duration of the annuity in years 
j = nominal interest rate 
m = conversions per year 

Write a program to determine the eventual cash value after requesting the necessary information. To test use r=2000 p=12 n=20 j=13% m=2, you should get 180,330.40

//
// value of an annuity
//
#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;


int main()
{
    float r;  //  payment per year 
    float p;  //  installments per year 
    float n;  //  duration of the annuity in yea
    float j;  //  nominal interest rate 
    float m;  //  conversions per year
    float x;  //  working variable
    float numerator, denominator;
    float s;  // eventual value
    
    cout << "Enter the payment per year : ";
    cin >> r;
    cout << "Enter the installments per year : ";
    cin >> p;
    cout << "Enter the duration of the annuity in years :";
    cin >> n;
    cout << "Enter the nominal interest rate :";
    cin >> j;  
    cout << "Enter the conversions per year : ";
    cin >> m;
    
    if(j > 1.0) j/=100.0;
    
    x=1 + j/m;
    
    numerator=pow(x,m*n)-1;
    denominator=p * (pow(x,m/p)-1);
    
    s=r*(numerator/denominator);
    
    cout << setiosflags( ios:: showpoint | ios::fixed);
    cout << "The cash value of this annuity is " 
         << setprecision(2) << s << endl;
         
    system("pause");
    return(0);
 
}

Enter the payment per year : 2000
Enter the installments per year : 12
Enter the duration of the annuity in years :20
Enter the nominal interest rate :13
Enter the conversions per year : 2
The cash value of this annuity is 180330.44
Press any key to continue . . .