C++ continue语句

#include <iostream>

using namespace std;

int main () {
   // Local variable declaration:
   int a = 10;

   // do loop execution
   do {
      if( a == 15) {
         // skip the iteration.
         a = a + 1;
         continue;
      }
      cout << "value of a: " << a << endl;
      a = a + 1;
   } 
   while( a < 20 );

   return 0;
}