C#实现对字符串中特定词出现次数的计数过程

string sentence = "The quick brown fox jumps over the lazy dog.";
string[] words = sentence.Split(' ');

from word in words
group word by word into wordGroup
select new
{
    Word = wordGroup.Key,
    Count = wordGroup.Count()
};

var result = from word in words
             group word by word into wordGroup
             select new
             {
                 Word = wordGroup.Key,
                 Count = wordGroup.Count()
             }
             where wordGroup.Key == "the"
             select wordGroup.Key;

var count = result.ToList().Count();
Console.WriteLine("The word 'the' appears {0} times.", count);

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        string sentence = "The quick brown fox jumps over the lazy dog.";
        string wordToCount = "the";

        // 使用LINQ前的传统方法
        int count = sentence.Split(' ')
                             .Count(w => w.ToLower() == wordToCount.ToLower());

        Console.WriteLine($"The word '{wordToCount}' appears {count} times.");
    }
}

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        string sentence = "The quick brown fox jumps over the lazy dog.";
        string wordToCount = "the";

        // 使用LINQ的Query Syntax
        int count = sentence.Split(' ')
                             .GroupBy(w => w.ToLower())
                             .Where(g => g.Key == wordToCount.ToLower())
                             .Select(g => g.Key)
                             .Count();

        Console.WriteLine($"The word '{wordToCount}' appears {count} times.");
    }
}

using System;
using System.Linq;

class Program
{
    static void Main()
    {
        string sentence = "The, quick brown fox jumps! over the lazy dog.";
        string wordToCount = "the";

        // 使用LINQ前的传统方法
        int count = sentence.Split(new char[] { ' ', ',', '.' }, StringSplitOptions.RemoveEmptyEntries)
                             .Count(w => w.ToLower() == wordToCount.ToLower());

        Console.WriteLine($"The word '{wordToCount}' appears {count} times.");
    }
}