请问list中如何统计相同值的个数?

Question

如题.比如list中值如下
100
100
110
110
100
115
110
100
120
110
100
请问如何统计100有多个少,110有多少个等等.
谢谢.

Answer 1

我的意思是不用for,list中有这个方法吗?

Answer 2

            List<int> list = new List<int>() { 12 , 12 , 13, 13, 14, 15, 15, 15 };            var g = list.GroupBy(i => i);            foreach (var item in g)
            {
                Console.WriteLine("Value:{0} , Count:{1}", item.Key, item.Count());
            }

Answer 3

using System;
using System.Collections.Generic;public class Example
{
    public static void Main()
    {
        List<string> dinosaurs = new List<string>();        dinosaurs.Add("Compsognathus");
        dinosaurs.Add("Amargasaurus");
        dinosaurs.Add("Oviraptor");
        dinosaurs.Add("Velociraptor");
        dinosaurs.Add("Deinonychus");
        dinosaurs.Add("Dilophosaurus");
        dinosaurs.Add("Gallimimus");
        dinosaurs.Add("Triceratops");        Console.WriteLine();
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }        Console.WriteLine("\nTrueForAll(EndsWithSaurus): {0}",
            dinosaurs.TrueForAll(EndsWithSaurus));        Console.WriteLine("\nFind(EndsWithSaurus): {0}", 
            dinosaurs.Find(EndsWithSaurus));        Console.WriteLine("\nFindLast(EndsWithSaurus): {0}",
            dinosaurs.FindLast(EndsWithSaurus));        Console.WriteLine("\nFindAll(EndsWithSaurus):");
        List<string> sublist = dinosaurs.FindAll(EndsWithSaurus);        foreach(string dinosaur in sublist)
        {
            Console.WriteLine(dinosaur);
        }        Console.WriteLine(
            "\n{0} elements removed by RemoveAll(EndsWithSaurus).", 
            dinosaurs.RemoveAll(EndsWithSaurus));        Console.WriteLine("\nList now contains:");
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }        Console.WriteLine("\nExists(EndsWithSaurus): {0}", 
            dinosaurs.Exists(EndsWithSaurus));
    }    // Search predicate returns true if a string ends in "saurus".
    private static bool EndsWithSaurus(String s)
    {
        if ((s.Length > 5) && 
            (s.Substring(s.Length - 6).ToLower() == "saurus"))
        {
            return true;
        }
        else
        {
            return false;
        }
    }
}

Answer 4

list.FindAll(delegate(int n) { return n == 100; }).Count

Answer 5

List<int> list = new List<int>();
            list.Add(100);
            list.Add(100);
            list.Add(100);
            list.Add(100);
            list.Add(100);
            MessageBox.Show(list.FindAll((ex) => { return ex == 100; }).Count.ToString());嘿嘿,可行