C# Lambda || Linq 效率问题

255条数据

      static void Main()
        {
            List<IPEndPoint> list = new List<IPEndPoint>();
            for (int i =0;i<=255;i++)
            {
                int j = 34 + i / 255;
                string ip = "188.10." + j + "." + i % 255;
                int port = 26666;
                IPAddress addr = IPAddress.Parse(ip);
                IPEndPoint host = new IPEndPoint(addr, port);
                list.Add(host);
            }

            System.Diagnostics.Stopwatch stop = new System.Diagnostics.Stopwatch();
            stop.Start();
            List<IPAddress> ips = new List<IPAddress>();
            foreach (var item in list)
            {
                if (item.Address.ToString()=="188.10.34.140")
                {
                    ips.Add(item.Address);
                }
            }
            stop.Stop();
            double mili = stop.Elapsed.TotalMilliseconds;
            Console.WriteLine("loop:		"+mili);
            Console.WriteLine("loopCount:	"+ips.Count);

            System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
            watch.Start();
            List<IPAddress> lists = list.Where(e => e.Address.ToString() == "188.10.34.140").Select(e => e.Address).ToList<IPAddress>();
            watch.Stop();
            double milis = watch.Elapsed.TotalMilliseconds;
            Console.WriteLine("lambda:		"+milis);
            Console.WriteLine("lambdaCount:	"+lists.Count);
        }

结果

loop:		0.0951
loopCount:	1
lambda:		0.5711
lambdaCount:	1

2550条

···
static void Main()
{
List list = new List();
for (int i =0;i<=2550;i++)
{
int j = 34 + i / 255;
string ip = "188.10." + j + "." + i % 255;
int port = 26666;
IPAddress addr = IPAddress.Parse(ip);
IPEndPoint host = new IPEndPoint(addr, port);
list.Add(host);
}

        System.Diagnostics.Stopwatch stop = new System.Diagnostics.Stopwatch();
        stop.Start();
        List<IPAddress> ips = new List<IPAddress>();
        foreach (var item in list)
        {
            if (item.Address.ToString()=="188.10.34.140")
            {
                ips.Add(item.Address);
            }
        }
        stop.Stop();
        double mili = stop.Elapsed.TotalMilliseconds;
        Console.WriteLine("loop:		"+mili);
        Console.WriteLine("loopCount:	"+ips.Count);

        System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
        watch.Start();
        List<IPAddress> lists = list.Where(e => e.Address.ToString() == "188.10.34.140").Select(e => e.Address).ToList<IPAddress>();
        watch.Stop();
        double milis = watch.Elapsed.TotalMilliseconds;
        Console.WriteLine("lambda:		"+milis);
        Console.WriteLine("lambdaCount:	"+lists.Count);
    }

···

结果

loop:		0.4618
loopCount:	1
lambda:		0.6283
lambdaCount:	1

25500条

      static void Main()
        {
            List<IPEndPoint> list = new List<IPEndPoint>();
            for (int i =0;i<=25500;i++)
            {
                int j = 34 + i / 255;
                string ip = "188.10." + j + "." + i % 255;
                int port = 26666;
                IPAddress addr = IPAddress.Parse(ip);
                IPEndPoint host = new IPEndPoint(addr, port);
                list.Add(host);
            }

            System.Diagnostics.Stopwatch stop = new System.Diagnostics.Stopwatch();
            stop.Start();
            List<IPAddress> ips = new List<IPAddress>();
            foreach (var item in list)
            {
                if (item.Address.ToString()=="188.10.34.140")
                {
                    ips.Add(item.Address);
                }
            }
            stop.Stop();
            double mili = stop.Elapsed.TotalMilliseconds;
            Console.WriteLine("loop:		"+mili);
            Console.WriteLine("loopCount:	"+ips.Count);

            System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
            watch.Start();
            List<IPAddress> lists = list.Where(e => e.Address.ToString() == "188.10.34.140").Select(e => e.Address).ToList<IPAddress>();
            watch.Stop();
            double milis = watch.Elapsed.TotalMilliseconds;
            Console.WriteLine("lambda:		"+milis);
            Console.WriteLine("lambdaCount:	"+lists.Count);
        }

结果

loop:		5.0348
loopCount:	1
lambda:		1.5531
lambdaCount:	1

猜想

Linq好像转化为stream再做处理，所以数据量少的时候比较占用时间，但是好省代码量。我也不懂Linq，只会用