1到10求和

#include <iostream>  //while xunhuan
int main()
{
  int sum = 0, val = 1;
  //keep executing the while until val is greater than 10
  while (val<=10){
    sum += val;
    ++val;
  }
  std::cout << "sum of 1 to 10 inclusive is"
            << sum <<std::endl;
   return 0;
}

for循环实例：

#include <iostream>

int main()

{

    int sum = 0;

   //sum values from 1 up to 10 inclusive

   for (int val =1; val <=10; ++val)

       sum += val; //equivalent to sum =sum+val

   std::cout << "sum of 1 to 10 inclusive is "

                 <<sum <<std::endl;

   return 0;

}