哪一个是更快的名单，其中，T＆GT;或ArrayList的＆LT; T＆GT;？ [英] Which one is faster List<T> or ArrayList<T>?

问题描述

可能重复：
   .NET：ArrayList的VS列表

您好，

我在网上搜索着，找我矛盾的答案，至今不清楚的， 哪一个是更快名单，其中，T＆GT;或ArrayList的＆LT; T＆GT; 键，是什么原因

I searched around the web and find my conflicting answers and so far unclear as to, Which one is faster List<T> or ArrayList<T> and what is the reason?

我猜名单，其中，T＆GT; 要快，但不知道在这种特殊情况下，甚至的ArrayList＆LT; T＆GT; 也被标记为一个泛型类型。

I am guessing List<T> should be faster but not sure as in this specific case even ArrayList<T> also is marked as a generic type.

许多感谢， 玛尼

推荐答案

我做了这个给你。

   static void Main(string[] args)
    {
        Stopwatch sw = new Stopwatch();
        Console.WriteLine("Adding a million 32bit integers");

        sw.Start();
        List<int> listA = new List<int>();
        for(int i = 0; i < 1000000; i++)
        {
            listA.Add(i);
        }
        sw.Stop();
        Console.WriteLine("List<int> took {0} ms", sw.ElapsedMilliseconds);
        sw.Reset();

        sw.Start();
        List<object> listB = new List<object>();
        for (int i = 0; i < 1000000; i++)
        {
            listB.Add(i);
        }
        sw.Stop();
        Console.WriteLine("List<object> took {0} ms", sw.ElapsedMilliseconds);
        sw.Reset();

        sw.Start();
        ArrayList listC = new ArrayList();
        for(int i = 0; i < 1000000; i++)
        {
            listC.Add(i);
        }
        sw.Stop();
        Console.WriteLine("ArrayList took {0} ms", sw.ElapsedMilliseconds);
        sw.Reset();

        Console.WriteLine("\n Inserting 1000 values");
        //Gen list of random numbers
        Random rand = new Random(12345);
        int[] insertlocs = new int[1000];
        for (int i = 0; i < insertlocs.Length; i++)
            insertlocs[i] = rand.Next(1, 999999);

        sw.Start();
        for (int i = 0; i < insertlocs.Length; i++)
        {
            listA.Insert(insertlocs[i], i);
        }
        sw.Stop();
        Console.WriteLine("List<int> took {0} ms", sw.ElapsedMilliseconds);
        sw.Reset();

        sw.Start();
        for (int i = 0; i < insertlocs.Length; i++)
        {
            listB.Insert(insertlocs[i], i);
        }
        sw.Stop();
        Console.WriteLine("List<object> took {0} ms", sw.ElapsedMilliseconds);
        sw.Reset();

        sw.Start();
        for (int i = 0; i < insertlocs.Length; i++)
        {
            listC.Insert(insertlocs[i], i);
        }
        sw.Stop();
        Console.WriteLine("ArrayList took {0} ms", sw.ElapsedMilliseconds);
        sw.Reset();

        Console.ReadKey();
    }

在我的补偿，名单，其中，INT＆GT; 拿了13毫秒，名单，其中，对象＆gt; 了69ms，的ArrayList 40毫秒了。

On my comp, List<int> took 13ms, List<object> took 69ms, ArrayList took 40ms.

如果你拥有它，对于引用类型的ArrayList更快。但是，值类型很显然你应该使用List

So there you have it, for reference types ArrayList is faster. But for value types you should obviously use List

编辑：测试插入性能也一样，名单，其中，INT＆GT; 了255毫秒，名单，其中，对象＆gt; 了723ms， 的ArrayList 了397ms。 ArrayList中的拳击的是几乎等同于没有列出拳！

Testing insert performance too, List<int> took 255ms, List<object> took 723ms, ArrayList took 397ms. ArrayList with boxing is almost on par with List without boxing!

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