do...while loop

• The while and for loops test the termination condition at the top.
• By contrast, the third loop in C++, the do-while,
  tests condition at the bottom:

  
          #include <iostream>
          int main()
          {
              int idx = 0;
              // Prints 01234:
              do {
                  std::cout << idx;
              } while ( ++idx < 5 );
              return 0;
          }