How to get the second most frequent word from the text?

Question

Here is my code:

string StringFromTheInput = TextBox1.Text;

string source = StringFromTheInput.ToString();

var frequencies = new Dictionary<string, int>();
frequencies.Add("item", 0);
string highestWord = null;

var message = string.Join(" ", source);
var splichar = new char[] { ' ', '.' };
var single = message.Split(splichar);
           
int highestFreq = 0;

foreach (var item in single)
{
    if (item.Length > 4)
    {
        int freq;
        frequencies.TryGetValue(item, out freq);
        freq += 1;

        if (freq> highestFreq)
        {
            highestFreq = freq;
            highestWord = item.Trim();
        }
                        
        frequencies[item] = freq;
        Label1.Text = highestWord.ToString();
    }
                
}

This is successfully gets me the most frequent word from the text but I tried to increment highestFreq= freq+1 to get the second most frequent word but it doesn`t work!

`doesn't gives me the second most frequent word` what does it give instead? — Chetan, Nov 10 '22 at 07:11
unrelated: `string source = StringFromTheInput.ToString();` this is not necessary. `TextBox1.Text` is already a `string`. It won't get any stringier. — Fildor, Nov 10 '22 at 07:15
If you have a dictionnary with word and their frequency. you can order by frequency and take all he element that have the frequency — Drag and Drop, Nov 10 '22 at 07:16
Chetan -it gives another word but not the second most frequent I am new to propgramming can you help me? — user20465780, Nov 10 '22 at 07:39
When you speak the most frequent word, I'm assuming the words MATCH 100% no difference? — ThisQRequiresASpecialist, Nov 10 '22 at 07:43
@ThisQRequiresASpecialist I guess you mean for example "Word" and "word" are two different words you are assuming? — Fildor, Nov 10 '22 at 07:45
Ando also: `if (item.Length > 4)` - you seem to only count words with at least 5 chars? — Fildor, Nov 10 '22 at 07:47

LoLo2207 · Answer 1 · 2022-11-10T07:51:32.280

Can you use Linq or is this homework?

using System;
using System.Linq;

string StringFromTheInput = "Her life in the confines of the house became her new normal. He wondered if she would appreciate his toenail collection. My secretary is the only person who truly understands my stamp-collecting obsession. This is the last random sentence I will be writing and I am going to stop mid-sent. She tilted her head back and let whip cream stream into her mouth while taking a bath.";

string[] words = StringFromTheInput.Split(" ");
var setsByFrequency = words
    .Where(x => x.Length > 4)   // For words with more than 4 characters
    .GroupBy(x => x.ToLower()) // ToLower so 'House' and 'house' both gets placed into the same group
    .Select(g => new { Freq = g.Count(), Word = g.Key})  
    .OrderByDescending(g => g.Freq)
    .ToList();

var mostFrequent = setsByFrequency[0];
var secondMostFrequent = setsByFrequency[1];

Console.WriteLine(mostFrequent);
Console.WriteLine(secondMostFrequent);

`ToLower()` is not a bad start but may not always work. See also https://learn.microsoft.com/en-us/dotnet/api/system.string.tolowerinvariant?redirectedfrom=MSDN&view=net-7.0#System_String_ToLowerInvariant — Fildor, Nov 10 '22 at 07:54
This works well can you help me please at this one? https://stackoverflow.com/questions/74390064/find-a-word-in-a-textbox1-and-if-it-found-add-the-line-to-textbox2?noredirect=1#comment131325430_74390064 — user20465780, Nov 10 '22 at 14:24

Siegfried.V · Answer 2 · 2022-11-10T07:55:57.630

0

you can order your Dictionary by their value, then take the first, second... element found.

int indexYouNeed =2;
int indexRead=1;
string textFound="";
foreach (KeyValuePair<string,int> entry in frequencies.Where(x=>x.Key.Length>4).OrderBy(x=>x.Value))
{
    if(indexRead==indexYouNeed)
    {
        textFound=entry.Key;
        break;
    }
    indexRead++;
}

edited Nov 10 '22 at 07:55

answered Nov 10 '22 at 07:40

Siegfried.V

1,508
1
16
34

1

If you have an ordered collection, you can also index the second element. You'd only need to loop if you wanted to make sure the second element has actually less count than the first instead of equal. – Fildor Nov 10 '22 at 07:43
@Fildor I know about Ordered collections, but to be honnest, I never used them, that's why I offered a solution that I understand (and so he would). But you're right, if anybody would answer with ordered collection, this would be the best solution. – Siegfried.V Nov 10 '22 at 07:48

score 0 · Answer 3 · answered Nov 10 '22 at 10:59

I would do something like this (simple and easy to understand) First, load the dictionary with your words and the frequency (only words with more than 4 characters, because I saw in your question that), in this case the dictionary must ignore case. Second, order the dictionary and take the second (please check if it is empty, or if it has only 1 element before trying to access):

string StringFromTheInput = "";
var wordsFreq = new Dictionary<string,int>(StringComparer.OrdinalIgnoreCase);
foreach(var s in StringFromTheInput.Split(' ')){
    if(s.Length <=4) continue;
    if(wordsFreq.ContainsKey(s)){
        wordsFreq[s]++; 
    }else{
        wordsFreq.Add(s,1);
    }
}
if(!wordsFreq.Any()) return;
var secondFreqWord = wordsFreq.OrderByDescending(x => x.Value).ToList()[1];

How to get the second most frequent word from the text?

3 Answers3