C++ using Loop and Input and Output Progam

Break and continue

#include 

#include

using namespace std;

 int main() 

{

   int number = 1;

   while (true) 

     {

      ++number;

      if ((number % 3) == 0) continue;

      if (number == 133) break;

      if ((number % 2) == 0) 

     {

         number += 3;

      } 

      else 

      {

         number -= 3;

      }

      cout << number << " ";

   }

   cout << endl;

   return 0;

}

Nested Loops

#include 

#include

using namespace std;

int main() 

{

   int size = 8;

   for (int row = 1; row <= size; ++row) 

   {   

      for (int col = 1; col <= size; ++col) 

   {  

         cout << "# ";

      }

      cout << endl; 

   }

    return 0;

}

String Input & output

#include 

#include

#include      

#include 

using namespace std;  

int main() 

{

   string message("Hello");

   cout << message << endl;

   cout << "Enter a message (no space): ";

   cin >> message;

   cout << message << endl;

   cin.ignore(numeric_limits::max(), '\n');

   cout << "Enter a message (with spaces): ";

   getline(cin, message);  

   cout << message << endl;

   return 0;

}

 Output Formatting

#include 

#include

#include    

using namespace std;

int main() 

{

   double pi = 3.14159265;

   cout << fixed << setprecision(4); 

   cout << pi << endl;

   cout << "|" << setw(8) << pi << "|" << setw(10) << pi << "|" << endl;

   cout << setfill('-');

   cout << "|" << setw(8) << pi << "|" << setw(10) << pi << "|" << endl;

   cout << scientific;  

   cout << pi << endl;

   bool done = false;

   cout << done << endl;  

   cout << boolalpha;     

   cout << done << endl;

   return 0;

}

Input Formatting

#include 

#include

#include 

#include 

using namespace std;

 int main() 

{

   string areacode, phonecode;

   string instr;

   cout << "Enter your phone number in this format (xxx)xxx-xxxx : ";

   cin.ignore();   

   cin >> setw(3) >> areacode;

   cin.ignore();   

   cin >> setw(3) >> phonecode;

   cin.ignore();   

   cin >> setw(4) >> instr;

   phonecode += instr;

   cout << "Phone number is (" << areacode << ")"<< phonecode.substr(0, 3) << "-"<< phonecode.substr(3, 4) << endl;  

   return 0;

}

  Array and Loop

#include 

#include

#include 

#include 

#define size 7

using namespace std;

int main() 

{

   int marks[] = {74, 43, 58, 60, 90, 64, 70};

   int sum = 0;

   int sumsq = 0;

   double mean, stddev;

   for (int i = 0; i < size; ++i) 

  {

      sum += marks[i];

      sumsq += marks[i]*marks[i];

   }

   mean = (double)sum/size;

   cout << fixed << "Mean is " << setprecision(2) << mean << endl;

   stdDev = sqrt((double)sumsq/size - mean*mean);

   cout << fixed << "Std dev is " << setprecision(2) << stddev << endl;

   return 0;

}

Range-based for loop

#include 

#include

using namespace std;

int main() 

{

   int numbers[] = {11, 22, 33, 44, 55};

   for (int number : numbers) 

  {

      cout << number << endl;

   }

   for (int &number : numbers)  

  {

      number = 99;

   }

   for (int number : numbers) 

  {

      cout << number << endl;

   }

   return 0;

}