cppreference.com > C/C++ Keywords > for for Syntax:
      for( initialization; test-condition; increment ) {
      statement-list;
      }
The for construct is a general looping mechanism consisting of 4 parts: the initialization, which consists of 0 or more comma-delimited variable initialization statements the test-condition, which is evaluated to determine if the execution of the for loop will continue the increment, which consists of 0 or more comma-delimited statements that increment variables 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!
       }
Related topics: break continue do if while