// Fig. 2.20: fig02_20.cpp
// Summation with for.
#include <iostream>
    
using std::cout;
using std::endl;
    
// function main begins program execution
int main()
{
  int sum = 0;                       // initialize sum
   
  // sum even integers from 2 through 100
  for ( int number = 2; number <= 100; number += 2 )     
    sum += number;                  // add number to sum
   
  cout << "Sum is " << sum << endl;  // output sum

  // Example with multiple variables
  for ( int i = 0, j = 0; j+1 <= 10; j++, i++ )     
    cout << "i: "<<i<<" j: "<<j<<" i+j: " << i+j << endl;  // output sum


  return 0;                          // successful termination
   
} // end function main