计算C＃文本文件中的特定单词

Question

If i got a text file

"dont run if you cant hide, or you will be broken in two strings, your a evil man"

and i want to count how many times the word you is in the text file, and put that value in to a int variable.

how do i go about doing somthing like that?

Answer 1

To say it with a Regex...

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)

or if you need the word you as stand-alone

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)

Edit: Replaced \\s+you\\s+ with (?i)\\byou\\b for the sake of correctness

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);

Ideally punctuation should be ignored. I'll let you handle a messy detail like that.

Answer 3

Assuming there are regular line breaks then if the file is huge this would be less memory intensive than some other approaches here. Uses Jason's counting method:

        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;
            }
        }

Or, combining the Scoregraphic's answer here with a IEnumerable method:

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

You could get a nifty one-liner

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

[Edited because System.IO.File now supports enumerating the lines of a file, removing need for hand rolled method of doing the same thing described above]

Or using framework method File.ReadLines() you could reduce this to:

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

Answer 4

Reading from a file:

int count;

using (StreamReader reader = File.OpenText("fileName")
{
   string contents = reader.ReadToEnd();
   MatchCollection matches = Regex.Matches(contents, "\byou\b");
   count = matches.Count;
}

Note that if you use " \\byou\\b " will match just the word "you" by itself. If you want to match "you" inside of other words (for example, the "you" in "your"), use "you" as the pattern instead of "\\byou\\b".

Answer 5

try regular expressions:

Regex r = new Regex("test");
MatchCollection matches = r.Matches("this is a test of using regular expressions to count how many times test is said in a string");
int iCount = matches.Count;

Answer 6

The following method will do the job.

public Int32 GetWordCountInFile(String fileName, String word, Boolean ignoreCase)
{
    return File
        .ReadAllText(fileName)
        .Split(new [] { ' ', '.', ',' })
        .Count(w => String.Compare(w, word, ignoreCase));
}

Maybe you will have to add a few other possible separators to the String.Split() call.

Answer 7

Try counting the occurances using indexOf and then moving to the next entry. Eg

using System;

namespace CountOcc
{
 class Program
 {
  public static void Main(string[] args)
  {
   int         StartPos; // Current pos in file.

   System.IO.StreamReader sr = new System.IO.StreamReader( "c:\\file.txt" );
   String Str = sr.ReadToEnd();

   int Count = 0;
   StartPos = 0;
   do
   {
    StartPos = Str.IndexOf( "Services", StartPos );
    if ( StartPos >= 0 )
    {
     StartPos++;
     Count++;
    }
   } while ( StartPos >= 0 );

   Console.Write("File contained " + Count + " occurances");
   Console.ReadKey(true);
  }
 }
}