for

  for( initialization; test-condition; increment ) {
  statement-list;
  }

The for construct is a general looping mechanism consisting of 4 parts:

1. the initialization, which consists of 0 or more comma-delimited variable initialization statements
2. the test-condition, which is evaluated to determine if the execution of the for loop will continue
3. the increment, which consists of 0 or more comma-delimited statements that increment variables
4. and the statement-list, which consists of 0 or more statements that will be executed each time the loop is executed.

For example:

   for( int i = 0; i < 10; i++ ) {
     cout << "i is " << i << endl;
   }
   int j, k;
   for( j = 0, k = 10;
        j < k;
        j++, k-- ) {
     cout << "j is " << j << " and k is " << k << endl;
   }
   for( ; ; ) {
     // loop forever!
   }