linq対foreachのコード

linq_vs_foreach.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LinqTest
{
    class Program
    {
        static void Main(string[] args)
        {
             var range1 = Enumerable.Range(1, 10000000);
            var range2 = Enumerable.Range(1, 10000000);
            var range3 = Enumerable.Range(1, 10000000);
            var start = DateTime.Now;
            var list1 = range1.Where(_ => _ % 2 == 0)
                        .Select(_ => (float)_)
                        .ToList();
            Console.WriteLine("{0} ms", (double)(DateTime.Now.Ticks - start.Ticks) / TimeSpan.TicksPerMillisecond);
            start = DateTime.Now;
            var list2 = new List<float>();
            foreach (var it in range2)
            {
                if (it % 2 == 0)
                    continue;
                list2.Add(it);
            }
            Console.WriteLine("{0} ms", (double)(DateTime.Now.Ticks - start.Ticks) / TimeSpan.TicksPerMillisecond);
            start = DateTime.Now;
            var list3 = new List<float>();
            foreach (var it in range3.Where(_ => _ % 2 == 0).Select(_ => (float)_))
            {
                list3.Add(it);
            }
            Console.WriteLine("{0} ms", (double)(DateTime.Now.Ticks - start.Ticks) / TimeSpan.TicksPerMillisecond);
            Console.WriteLine("counts: {0}, {1}, {2}", list1.Count, list2.Count, list3.Count);
            Console.ReadLine();
        }
    }
}