[user02@FC4 Lesson09]$ cat -n loopvar.cpp

   1  #include <iostream>
   2  using namespace std;
   3
   4  int main()
   5  {
   6     char letter;
   7     float value;
   8
   9     for (letter = 'A'; letter <= 'Z'; letter++)
  10        cout << letter;
  11
  12     cout << endl;
  13
  14     for (value = 0.0; value <= 1.0; value += 0.1)
  15        cout << value << ' ';
  16
  17     cout << endl;
  18
  19     return 0;
  20  }

[user02@FC4 Lesson09]$ g++ -o loopvar loopvar.cpp
[user02@FC4 Lesson09]$ ./loopvar
ABCDEFGHIJKLMNOPQRSTUVWXYZ
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9