Show what is Deferred Query Execution in CSharp

/* ww  w .  j a v  a  2  s . c  om*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class MainClass {
    public static void Main() {
        int[] numbers = new int[] { 5, 4, 1, 3, 9 };

        int i = 0;
        var q =
            from n in numbers
            select ++i;
        foreach (var v in q) {
            Console.WriteLine("v = {0}, i = {1}", v, i);
        }
    }
}