using namespace std;
#include <iostream>        // This is a key C++ library
#include <cmath>           // The standard C library math.h

int main ()
{
   double a;

   a = 1.2;
   a = sin (a);

   cout << a << endl;

   return 0;
}

using namespace std;         // Using the standard library namespace.
#include <iostream>          // The iostream library is often used.

int main ()                  // The program's main routine.
{
   double a;                 // Declaration of variable a.

   a = 456.47;
   a = a + a * 21.5 / 100;   // A calculation.

   cout << a << endl;        // Display the content of a.

   return 0;                 // Program end.
}

using namespace std;
#include <iostream>

void main()
{
   int a;                    // a is an integer variable
   char s [100];             // s points to a string of max 99 characters

   cout << "This is a sample program." << endl;

   cout << endl;             // Just a line feed (end of line)

   cout << "Type your age : ";
   cin >> a;

   cout << "Type your name: ";
   cin >> s;

   cout << endl;

   cout << "Hello " << s << " you're " << a << " old." << endl;
   cout << endl << endl << "Bye!" << endl;

   return 0;
}

using namespace std;
#include <iostream>

int main ()
{
   double a;

   cout << "Type a number: ";
   cin >> a;

   {
      int a = 1;
      a = a * 10 + 4;
      cout << "Local number: " << a << endl;
   }

   cout << "You typed: " << a << endl;

   return 0;
}

using namespace std;
#include <iostream>

int main ()
{
   double a = 12 * 3.25;
   double b = a + 1.112;

   cout << "a contains: " << a << endl;
   cout << "b contains: " << b << endl;

   a = a * 2 + b;

   double c = a + b * a;

   cout << "c contains: " << c << endl;

   return 0;
}

using namespace std;
#include <iostream>

int main ()
{   
   int i;                       // Simple declaration of i
   i = 487;

   for (int i = 0; i < 4; i++)  // Local declaration of i 
   {
      cout << i << endl;        // This outputs 0, 1, 2 and 3
   }

   cout << i << endl;           // This outputs 487

   return 0;
}

using namespace std;
#include <iostream>

int main ()
{

   for (int i = 0; i < 4; i++)
   {
      cout << i << endl;
   }

   cout << i << endl;           // Bad practice!
   i += 5;                      // Bad practice!
   cout << i << endl;           // Bad practice!

   return 0;
}

using namespace std;
#include <iostream>

double a = 128;

int main ()
{
   double a = 256;

   cout << "Local a:  " << a   << endl;
   cout << "Global a: " << ::a << endl;

   return 0;
}

using namespace std;
#include <iostream>

int main ()
{
   double a = 3.1415927;

   double &b = a;                            // b is a

   b = 89;

   cout << "a contains: " << a << endl;     // Displays 89.

   return 0;
}

using namespace std;
#include <iostream>

void change (double &r, double s)
{
   r = 100;
   s = 200;
}

int main ()
{
   double k, m;

   k = 3;
   m = 4;

   change (k, m);

   cout << k << ", " << m << endl;        // Displays 100, 4.

   return 0;
}

using namespace std;
#include <iostream>

void change (double *r, double s)
{
   *r = 100;
   s = 200;
}

int main ()
{
   double k, m;

   k = 3;
   m = 4;

   change (&k, m);

   cout << k << ", " << m << endl;        // Displays 100, 4.

   return 0;
}

using namespace std;
#include <iostream>

double &biggest (double &r, double &s)
{
   if (r > s) return r;
   else       return s;
}

int main ()
{
   double k = 3;
   double m = 7;

   cout << "k: " << k << endl;       // Displays  3
   cout << "m: " << m << endl;       // Displays  7
   cout << endl;

   biggest (k, m) = 10;

   cout << "k: " << k << endl;       // Displays  3
   cout << "m: " << m << endl;       // Displays 10
   cout << endl;

   biggest (k, m) ++;

   cout << "k: " << k << endl;       // Displays  3
   cout << "m: " << m << endl;       // Displays 11
   cout << endl;

   return 0;
}

using namespace std;
#include <iostream>

double *biggest (double *r, double *r)
{
   if (*r > *s) return r;
   else         return s;
}

int main ()
{
   double k = 3;
   double m = 7;

   cout << "k: " << k << endl;
   cout << "m: " << m << endl;
   cout << endl;

   (*(biggest (&k, &m))) = 10;

   cout << "k: " << k << endl;
   cout << "m: " << m << endl;
   cout << endl;

   (*(biggest (&k, &m))) ++;

   cout << "k: " << k << endl;
   cout << "m: " << m << endl;
   cout << endl;

   return 0;
}

using namespace std;
#include <iostream>

double *silly_function ()    // This function returns a pointer to a double
{
   static double r = 342;
   return &r;
}

int main ()
{
   double *a;

   a = silly_function();

   double &b = *a;          // Now b is the double towards which a points!

   b += 1;                  // Great!
   b = b * b;               // No need to write *a everywhere!
   b += 4;

   cout << "Content of *a, b and r: " << b << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cmath>

namespace first
{
   int a;
   int b;
}

namespace second
{
   double a;
   double b;
}

int main ()
{
   first::a = 2;
   first::b = 5;

   second::a = 6.453;
   second::b = 4.1e4;

   cout << first::a + second::a << endl;
   cout << first::b + second::b << endl;

   return 0;
}

CAM simulator Sample with VC++ MFC Source Code

using namespace std;
#include <iostream>
#include <cmath>

inline double hypothenuse (double a, double b)
{
   return sqrt (a * a + b * b);
}

int main ()
{
   double k = 6, m = 9;

   // Next two lines produce exactly the same code:

   cout << hypothenuse (k, m) << endl;
   cout << sqrt (k * k + m * m) << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cmath>

int main ()
{
   int a, b;

   cout << "Type a number: ";
   cin >> a;
   cout << endl;

   try
   {
      if (a > 100) throw 100;
      if (a < 10)  throw 10;
      throw a / 3;
   }
   catch (int result)
   {
      cout << "Result is: " << result << endl;
      b = result + 1;
   }

   cout << "b contains: " << b << endl;

   cout << endl;

   // another example of exception use:

   char zero []     = "zero";
   char pair []     = "pair";
   char notprime [] = "not prime";
   char prime []    = "prime";

   try
   {
      if (a == 0) throw zero;
      if ((a / 2) * 2 == a) throw pair;
      for (int i = 3; i <= sqrt (a); i++)
      {
         if ((a / i) * i == a) throw notprime;
      }
      throw prime;
   }
   catch (char *conclusion)
   {
      cout << "The number you typed is "<< conclusion << endl;
   }

   cout << endl;

   return 0;
}

using namespace std;
#include <iostream>

double test (double a, double b = 7)
{
   return a - b;
}

int main ()
{
   cout << test (14, 5) << endl;    // Displays 14 - 5
   cout << test (14) << endl;       // Displays 14 - 7

   return 0;
}

using namespace std;
#include <iostream>

double test (double a, double b)
{
   return a + b;
}

int test (int a, int b)
{
   return a - b;
}

int main ()
{
   double   m = 7,  n = 4;
   int      k = 5,  p = 3;

   cout << test(m, n) << " , " << test(k, p) << endl;

   return 0;
}

using namespace std;
#include <iostream>

struct vector
{
   double x;
   double y;
};

vector operator * (double a, vector b)
{
   vector r;

   r.x = a * b.x;
   r.y = a * b.y;

   return r;
}

int main ()
{
   vector k, m;              // No need to type "struct vector"

   k.x =  2;                 // To be able to write
   k.y = -1;                 // k = vector (2, -1)
                             // see chapter 19.

   m = 3.1415927 * k;        // Magic!

   cout << "(" << m.x << ", " << m.y << ")" << endl;

   return 0;
}

using namespace std;
#include <iostream>

struct vector
{
   double x;
   double y;
};

ostream& operator << (ostream& o, vector a)
{
   o << "(" << a.x << ", " << a.y << ")";
   return o;
}

int main ()
{
   vector a;

   a.x = 35;
   a.y = 23;

   cout << a << endl;     // Displays (35, 23)

   return 0;
}

using namespace std;
#include <iostream>

template <class ttype>
ttype minimum (ttype a, ttype b)
{
   ttype r;

   r = a;
   if (b < a) r = b;

   return r;
}

int main ()
{
   int i1, i2, i3;
   i1 = 34;
   i2 = 6;
   i3 = minimum (i1, i2);
   cout << "Most little: " << i3 << endl;

   double d1, d2, d3;
   d1 = 7.9;
   d2 = 32.1;
   d3 = minimum (d1, d2);
   cout << "Most little: " << d3 << endl;

   cout << "Most little: " << minimum (d3, 3.5) << endl;

   return 0;
}

using namespace std;
#include <iostream>

template <class type1, class type2>
type1 minimum (type1 a, type2 b)
{
   type1 r, b_converted;
   r = a;
   b_converted = (type1) b;
   if (b_converted < a) r = b_converted;
   return r;
}

int main ()
{
   int i;
   double d;

   i = 45;
   d = 7.41;

   cout << "Most little: " << minimum (i, d) << endl;
   cout << "Most little: " << minimum (d, i) << endl;
   cout << "Most little: " << minimum ('A', i) << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cstring>

int main ()
{
   double *d;                         // d is a variable whose purpose
                                      // is to contain the address of a
                                      // zone where a double is located


   d = new double;                    // new allocates a zone of memory
                                      // large enough to contain a double
                                      // and returns its address.
                                      // That address is stored in d.

   *d = 45.3;                         // The number 45.3 is stored
                                      // inside the memory zone
                                      // whose address is given by d.

   cout << "Type a number: ";
   cin >> *d;

   *d = *d + 5;

   cout << "Result: " << *d << endl;

   delete d;                          // delete deallocates the
                                      // zone of memory whose address
                                      // is given by pointer d.
                                      // Now we can no more use that zone.


   d = new double[15];                // allocates a zone for an array
                                      // of 15 doubles. Note each 15
                                      // double will be constructed.
                                      // This is pointless here but it
                                      // is vital when using a data type
                                      // that needs its constructor be
                                      // used for each instance.

   d[0] = 4456;
   d[1] = d[0] + 567;

   cout << "Content of d[1]: " << d[1] << endl;

   delete [] d;                       // delete [] will deallocate the
                                      // memory zone. Note each 15
                                      // double will be destructed.
                                      // This is pointless here but it
                                      // is vital when using a data type
                                      // that needs its destructor be
                                      // used for each instance (the ~
                                      // method). Using delete without
                                      // the [] would deallocate the
                                      // memory zone without destructing
                                      // each of the 15 instances. That
                                      // would cause memory leakage.

   int n = 30;

   d = new double[n];                 // new can be used to allocate an
                                      // array of random size.
   for (int i = 0; i < n; i++)
   {
      d[i] = i;
   }

   delete [] d;


   char *s;

   s = new char[100];

   strcpy (s, "Hello!");

   cout << s << endl;

   delete [] s;

   return 0;
}

using namespace std;
#include <iostream>

struct vector
{
   double x;
   double y;

   double surface ()
   {
      double s;
      s = x * y;
      if (s < 0) s = -s;
      return s;
   }
};

int main ()
{
   vector a;

   a.x = 3;
   a.y = 4;

   cout << "The surface of a: " << a.surface() << endl;

   return 0;
}

using namespace std;
#include <iostream>

class vector
{
public:

   double x;
   double y;

   double surface ()
   {
      double s;
      s = x * y;
      if (s < 0) s = -s;
      return s;
   }
};

int main ()
{
   vector a;

   a.x = 3;
   a.y = 4;

   cout << "The surface of a: " << a.surface() << endl;

   return 0;
}

using namespace std;
#include <iostream>

class vector
{
public:

   double x;
   double y;

   vector its_oposite()
   {
      vector r;

      r.x = -x;
      r.y = -y;

      return r;
   }

   void be_oposited()
   {
      x = -x;
      y = -y;
   }

   void be_calculated (double a, double b, double c, double d)
   {
      x = a - c;
      y = b - d;
   }

   vector operator * (double a)
   {
      vector r;

      r.x = x * a;
      r.y = y * a;

      return r;
   }
};

int main ()
{
   vector a, b;

   a.x = 3;
   a.y = 5;

   b = a.its_oposite();

   cout << "Vector a: " << a.x << ", " << a.y << endl;
   cout << "Vector b: " << b.x << ", " << b.y << endl;

   b.be_oposited();
   cout << "Vector b: " << b.x << ", " << b.y << endl;

   a.be_calculated (7, 8, 3, 2);
   cout << "Vector a: " << a.x << ", " << a.y << endl;

   a = b * 2;
   cout << "Vector a: " << a.x << ", " << a.y << endl;

   a = b.its_oposite() * 2;
   cout << "Vector a: " << a.x << ", " << a.y << endl;

   cout << "x of oposite of a: " << a.its_oposite().x << endl;

   return 0;
}

using namespace std;
#include <iostream>

class vector
{
public:

   double x;
   double y;

   vector ()                     // same name as class
   {
      x = 0;
      y = 0;
   }

   vector (double a, double b)
   {
      x = a;
      y = b;
   }

};

int main ()
{
   vector k;                     // vector () is called

   cout << "vector k: " << k.x << ", " << k.y << endl << endl;

   vector m (45, 2);             // vector (double, double) is called

   cout << "vector m: " << m.x << ", " << m.y << endl << endl;

   k = vector (23, 2);           // vector created, copied to k, then erased

   cout << "vector k: " << k.x << ", " << k.y << endl << endl;

   return 0;
}

using namespace std;
#include <iostream>

class vector
{
public:

   double x;
   double y;

   vector (double a = 0, double b = 0)
   {
      x = a;
      y = b;
   }
};

int main ()
{
   vector k;
   cout << "vector k: " << k.x << ", " << k.y << endl << endl;

   vector m (45, 2);
   cout << "vector m: " << m.x << ", " << m.y << endl << endl;

   vector p (3);
   cout << "vector p: " << p.x << ", " << p.y << endl << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cstring>

class person
{
public:

   char *name;
   int age;

   person (char *n = "no name", int a = 0)
   {
      name = new char [100];                 // better than malloc!
      strcpy (name, n);
      age = a;
      cout << "Instance initialized, 100 bytes allocated" << endl;
   }

   ~person ()                               // The destructor
   {
      delete name;                          // instead of free!

                                            // delete [] name would be more
                                            // academic but it is not vital
                                            // here since the array contains
                                            // no C++ sub-objects that need
                                            // to be deleted.

      cout << "Instance going to be deleted, 100 bytes freed" << endl;
   }
};

int main ()
{
    cout << "Hello!" << endl << endl;

    person a;
    cout << a.name << ", age " << a.age << endl << endl;

    person b ("John");
    cout << b.name << ", age " << b.age << endl << endl;

    b.age = 21;
    cout << b.name << ", age " << b.age << endl << endl;

    person c ("Miki", 45);
    cout << c.name << ", age " << c.age << endl << endl;

    cout << "Bye!" << endl << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cstdlib>

class array
{
public:
   int size;
   double *data;

   array (int s)
   {
      size = s;
      data = new double [s];
   }

   ~array ()
   {
      delete [] data;
   }

   double &operator [] (int i)
   {
      if (i < 0 || i >= size)
      {
         cerr << endl << "Out of bounds" << endl;
         exit (EXIT_FAILURE);
      }
      else return data [i];
   }
};

int main ()
{
   array t (5);

   t[0] = 45;                       // OK
   t[4] = t[0] + 6;                 // OK
   cout << t[4] << endl;            // OK

   t[10] = 7;                       // error!

   return 0;
}

using namespace std;
#include <iostream>
#include <cstring>

class person
{
public:

   char *name;
   int age;

   person (char *n = "no name", int a = 0)
   {
      name = new char[100];
      strcpy (name, n);
      age = a;
   }

   person (const person &s)      // The COPY CONSTRUCTOR
   {
      name = new char[100];
      strcpy (name, s.name);
      age = s.age;
   }

   person& operator= (const person &s)  // overload of =
   {
      strcpy (name, s.name);
      age = s.age;
      return *this;
   }

   ~person ()
   {
      delete [] name;
   }
};

int main ()
{
   person p;
   cout << p.name << ", age " << p.age << endl << endl;

   person k ("John", 56);
   cout << k.name << ", age " << k.age << endl << endl;

   p = k;
   cout << p.name << ", age " << p.age << endl << endl;

   p = person ("Bob", 10);
   cout << p.name << ", age " << p.age << endl << endl;

   return 0;
}

using namespace std;
#include <iostream>

class vector
{
public:

   double x;
   double y;

   double surface();         // The ; and no {} show it is a prototype
};

double vector::surface()
{
   double s = 0;

   for (double i = 0; i < x; i++)
   {
      s = s + y;
   }

   return s;
}

int main ()
{
   vector k;

   k.x = 4;
   k.y = 5;

   cout << "Surface: " << k.surface() << endl;

   return 0;
}

class vector
{
public:

   double x;
   double y;

   double surface();
};

using namespace std;
#include "vector.h"

using namespace std;
#include <iostream>
#include "vector.h"

int main ()
{
   vector k;

   k.x = 4;
   k.y = 5;

   cout << "Surface: " << k.surface() << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cmath>

class vector
{
public:

   double x;
   double y;

   vector (double a = 0, double b = 0)
   {
      x = a;
      y = b;
   }

   double module()
   {
      return sqrt (x * x + y * y);
   }

   void set_length (double a = 1)
   {
      double length;

      length = this->module();

      x = x / length * a;
      y = y / length * a;
   }
};

int main ()
{
   vector c (3, 5);

   cout << "The module of vector c: " << c.module() << endl;

   c.set_length(2);            // Transforms c in a vector of size 2.

   cout << "The module of vector c: " << c.module() << endl;

   c.set_length();             // Transforms b in an unitary vector.

   cout << "The module of vector c: " << c.module() << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cmath>

class vector
{
public:

   double x;
   double y;

   vector (double a = 0, double b = 0)
   {
      x = a;
      y = b;
   }

   double module ()
   {
      return sqrt (x * x + y * y);
   }
};

int main ()
{
   vector s [1000];

   vector t[3] = {vector(4, 5), vector(5, 5), vector(2, 4)};

   s[23] = t[2];

   cout << t[0].module() << endl;

   return 0;
}

vector operator + (vector a, vector b)
{
   return vector (a.x + b.x, a.y + b.y);
}

vector operator * (double a, vector b)
{
   return vector (a * b.x, a * b.y);
}

using namespace std;
#include <iostream>

class vector
{
public:

   double x;
   double y;
   static int count;

   vector (double a = 0, double b = 0)
   {
      x = a;
      y = b;
      count++;
   }

   ~vector()
   {
      count--;
   }
};

int vector::count = 0;

int main ()
{
   cout << "Number of vectors:" << endl;

   vector a;
   cout << vector::count << endl;

   vector b;
   cout << vector::count  << endl;

   vector *r, *u;

   r = new vector;
   cout << vector::count << endl;

   u = new vector;
   cout << a.count << endl;

   delete r;
   cout << vector::count << endl;

   delete u;
   cout << b.count << endl;

   return 0;
}

using namespace std;
#include <iostream>

class vector
{
public:

   double x;
   double y;
   const static double pi = 3.1415927;

   vector (double a = 0, double b = 0)
   {
      x = a;
      y = b;
   }

   double cilinder_volume ()
   {
      return x * x / 4 * pi * y;
   }
};

int main()
{
   cout << "The value of pi: " << vector::pi << endl << endl;

   vector k (3, 4);

   cout << "Result: " << k.cilinder_volume() << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cmath>

class vector
{
public:

   double x;
   double y;

   vector (double a = 0, double b = 0)
   {
      x = a;
      y = b;
   }

   double module()
   {
      return sqrt (x*x + y*y);
   }

   double surface()
   {
       return x * y;
   }
};

class trivector: public vector   // trivector is derived from vector
{
public:
   double z;                      // added to x and y from vector

   trivector (double m=0, double n=0, double p=0): vector (m, n)
   {
      z = p;                      // Vector constructor will
   }                              // be called before trivector
                                  // constructor, with parameters
                                  // m and n.

   trivector (vector a)           // What to do if a vector is
   {                              // cast to a trivector
      x = a.x;
      y = a.y;
      z = 0;
   }

   double module ()               // define module() for trivector
   {
      return sqrt (x*x + y*y + z*z);
   }

   double volume ()
   {
       return this->surface() * z;         // or x * y * z
   }
};

int main ()
{
   vector a (4, 5);
   trivector b (1, 2, 3);

   cout << "a (4, 5)    b (1, 2, 3)    *r = b" << endl << endl;

   cout << "Surface of a: " << a.surface() << endl;
   cout << "Volume of b: " << b.volume() << endl;
   cout << "Surface of base of b: " << b.surface() << endl;

   cout << "Module of a: " << a.module() << endl;
   cout << "Module of b: " << b.module() << endl;
   cout << "Module of base of b: " << b.vector::module() << endl;

   trivector k;
   k = a;               // thanks to trivector(vector) definition
                        // copy of x and y,       k.z = 0
   vector j;
   j = b;               // copy of x and y.       b.z leaved out

   vector *r;
   r = &b;

   cout << "Surface of r: " << r->surface() << endl;
   cout << "Module of r: " << r->module() << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <cmath>

class vector
{
public:

   double x;
   double y;

   vector (double a = 0, double b = 0)
   {
      x = a;
      y = b;
   }

   virtual double module()
   {
      return sqrt (x*x + y*y);
   }
};

class trivector: public vector
{
public:
   double z;

   trivector (double m = 0, double n = 0, double p = 0)
   {
      x = m;                  // Just for the game,
      y = n;                  // here I do not call the vector
      z = p;                  // constructor and I make the
   }                          // trivector constructor do the
                              // whole job. Same result.

   double module ()
   {
      return sqrt (x*x + y*y + z*z);
   }
};

void test (vector &k)
{
    cout << "Test result:          " << k.module() << endl;
}

int main ()
{
   vector a (4, 5);
   trivector b (1, 2, 3);

   cout << "a (4, 5)    b (1, 2, 3)" << endl << endl;

   vector *r;

   r = &a;
   cout << "module of vector a: " << r->module() << endl;

   r = &b;
   cout << "module of trivector b: " << r->module() << endl;

   test (a);

   test (b);

   vector &s = b;

   cout << "module of trivector b: " << s.module() << endl;

   return 0;
}

class octopus
{
   virtual double module() = 0;
};

class cuttlefish
{
   virtual int test() = 0;
};

class vector: public octopus, public cuttlefish
{
   double x;
   double y;

   double module ()
   {
      return sqrt (x * x + y * y);
   }

   int test ()
   {
      if (x > y) return 1;
      else       return 0;
   }
}

   void set_y (int n)
   {
      y = n;
   }

using namespace std;
#include <iostream>

class vector
{
protected:

   double x;
   double y;

public:

   void set_x (int n)
   {
      x = n;
   }

   void set_y (int n)
   {
      y = n;
   }

   double get_x ()
   {
      return x;
   }

   double get_y ()
   {
      return y;
   }

using namespace std;
#include <iostream>

int sign (double n)
{
   if (n >= 0) return 1;
   return -1;
}

class vector
{
protected:

   double x;
   double y;

public:

   void set_x (int n)
   {
      x = n;
      if (sign (x) != sign(y)) y = -y;
   }

   void set_y (int n)
   {
      y = n;
      if (sign (y) != sign(x)) x = -x;
   }

   double get_x ()
   {
      return x;
   }

   double get_y ()
   {
      return y;
   }

using namespace std;
#include <iostream>
#include <fstream>

int main ()
{
   fstream f;

   f.open("c:\\test.txt", ios::out);

   f << "This is a text output to a file." << endl;

   double a = 345;

   f  << "A number: " << a << endl;

   f.close();

   return 0;
}

using namespace std;
#include <iostream>
#include <fstream>

int main ()
{
   fstream f;
   char c;

   cout << "What's inside the test.txt file from";
   cout << "the C: hard disk root " << endl;
   cout << endl;

   f.open("c:\\test.txt", ios::in);

   while (! f.eof() )
   {
      f.get(c);                          // Or c = f.get()
      cout << c;
   }

   f.close();

   return 0;
}

using namespace std;
#include <iostream>
#include <strstream>
#include <cstring>
#include <cmath>

int main ()
{
   char a[1024];
   ostrstream b(a, 1024);

   b.seekp(0);                           // Start from first char.
   b << "2 + 2 = " << 2 + 2 << ends;     // ( ends, not endl )
                                         // ends is simply the
                                         // null character   '\0'
   cout << a << endl;

   double v = 2;

   strcpy (a, "A sinus: ");

   b.seekp(strlen (a));
   b << "sin (" << v << ") = " << sin(v) << ends;

   cout << a << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <strstream>
#include <cstring>

int main ()
{
   char a[1024];
   istrstream b(a, 1024);

   strcpy (a, "45.656");

   double k, p;

   b.seekg(0);                       // Start from first character.
   b >> k;

   k = k + 1;

   cout << k << endl;

   strcpy (a, "444.23 56.89");

   b.seekg(0);
   b >> k >> p;

   cout << k << ", " << p + 1 << endl;

   return 0;
}

using namespace std;
#include <iostream>
#include <iomanip>

int main ()
{
   int i;

   cout << "A list of numbers:" << endl;
   for (i = 1; i <= 1024; i *= 2)
   {
      cout.width (7);
      cout << i << endl;
   }

   cout << "A table of numbers:" << endl;
   for (i = 0; i <= 4; i++)
   {
      cout << setw(3) << i << setw(5) << i * i * i << endl;
   }

   return 0;
}

Using GDI+ with MFC or native C/VC++