Set numbers in a for loop

[markusfurst]

If I have this piece of code, how could I get it to output a number before each line. So that output would be something like this,

1 Barack            Obama            
2 Micheal           Phelps
3 Britney           Spears

for(auto& e : persons)
    {  
        cout << left << setw(20) << e.firstname;
        cout << setw(20) << e.lastname;
    }

[JewelCpp]

How about this:

    int i=1;
    for(auto& e : persons)
    {  
        cout << left <<  i << ' ' << setw(20) << e.firstname;
        cout << setw(20) << e.lastname;
        i++;
    }

[Chervil]

    for (auto& e : persons)
    {  
        static int n = 1;
        cout << right << setw(3)  << n++ << "  "
             << left  << setw(20) << e.firstname
             << setw(20) << e.lastname << '\n';
    } 

Declare n as static so it retains its value from one iteration to the next. (You could declare it outside the loop, but that is cluttering the outer scope with unnecessary variables).