Don't recognise this for loop

[greenfox]

Hi, I was going through Bjarne's book (Principles and Practice using C++ 2nd Ed.) and came across this for loop:

  double sum = 0;
  for(int x : temps)sum += x;    //where 'temps' is a vector of type double
  cout << "Average temperature: " << sum/temps.size() << '\n';

I just haven't seen the structure of this for loop before, and it doesn't explain the syntax as before he did with the usual for(;;).

Don't suppose anyone could help explain this?

Thanks in advance, Jack.

[JLBorges]

http://www.stroustrup.com/C++11FAQ.html#for

[greenfox]

Ahh, thank you very much JLBorges.