在C#中计算文本文件中的特定单词

Question

如果我有一个文本文件

"如果你不能隐藏,就不要跑,否则你会被打成两串,你是一个邪恶的男人"

我想计算你在文本文件中的单词的次数,并将该值放入int变量.

我怎么去做那样的事情？

Answer 1

用正则表达式来说...

Console.WriteLine((new Regex(@"(?i)you")).Matches("dont run if you cant hide, or you will be broken in two strings, your a evil man").Count)

或者如果你需要单独的单词

Console.WriteLine((new Regex(@"(?i)\byou\b")).Matches("dont run if you cant hide, or you will be broken in two strings, your a evil man").Count)

编辑:为了正确起见,用(？i)\ byou\b替换\ s +你\ s +

Answer 2

string s = "dont run if you cant hide, or you will be broken in two strings, your a evil man";
var wordCounts = from w in s.Split(' ')
                 group w by w into g
                 select new { Word = g.Key, Count = g.Count() };

int youCount = wordCounts.Single(w => w.Word == "you").Count;
Console.WriteLine(youCount);

理想情况下,应忽略标点符号.我会让你处理那样凌乱的细节.

Answer 3

假设存在常规换行符,那么如果文件很大,那么这将比其他方法的内存密集度更低.使用杰森的计数方法:

        var total = 0;
        using(StreamReader sr=new StreamReader("log.log"))
        {

            while (!sr.EndOfStream)
            {
                var counts = sr
                    .ReadLine()
                    .Split(' ')
                    .GroupBy(s => s)
                    .Select(g => new{Word = g.Key,Count = g.Count()});
                var wc = counts.SingleOrDefault(c => c.Word == "you");
                total += (wc == null) ? 0 : wc.Count;
            }
        }

或者,将Scoregraphic的答案与IEnumerable方法结合起来:

    static IEnumerable<string> Lines(string filename)
    {
        using (var sr = new StreamReader(filename))
        {
            while (!sr.EndOfStream)
            {
                yield return sr.ReadLine();
            }
        }
    }

你可以得到一个漂亮的单行

    Lines("log.log")
        .Select(line => Regex.Matches(line, @"(?i)\byou\b").Count)
        .Sum();

[编辑,因为System.IO.File现在支持枚举文件的行,删除需要手动滚动的方法做同样的事情]

或者使用框架方法,File.ReadLines()您可以将其减少为:

File.ReadLines("log.log")
        .Select(line => Regex.Matches(line, @"(?i)\byou\b").Count)
        .Sum();