xcode: undeclared identifier for vector

I am writing a very simple c++ code using xcode, but it kept returning undeclared identifier for i I'm really confused.

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;    
int main() {

            vector <int> v(4);
            v [0] = 25;
            v [1] = 15;
            v [2] = 10;
            v [3] = 5;

            sort (v.begin(), v.end());

            for (int i=0; i< v.size(); i++);
                cout << v[i]<< " ";
            cout << endl;

            return 0;
        }