How to find the 2nd longest word(s) in the text using C#, WinForm

Question

0.00/5 (No votes)

See more:

Hi all,

I'm wondering how to find the 2nd longest words in the text?

The following is the code for counting letters and words but I can't figure out how to put them together to get the out come of the 2nd longest words(red, and)...

I'm new to programming so simpler coding (must be in C#) would be great :)

Thank you all in advance~

Counting Letters

C#

int count = 0;
            string st = "I like apples. I like red apples. I like red apples and green bananas.";


            foreach (char c in st)
            {
                if (char.IsLetter(c))
                {
                    count++;
                }
            }

            lblNumOfLetters.Text = count.ToString();

Counting Words

C#

string st = "I like apples. I like red apples. I like red apples and green bananas.";

            char[] sep = { ' ' };

            String[] res = st.Split(sep);

            lblNumOfWords.Text = res.Length.ToString();

Posted 7-Nov-14 17:52pm

Member 10977819

Updated 7-Nov-14 18:16pm

PIEBALDconsult

v3

Add a Solution

Comments

BillWoodruff 8-Nov-14 1:19am

Do you need to remove punctuation before you analyze the word lengths ? So, using your sample string: "apple" and "apple," would both be considered the same words, with five characters ?

When you say: "the 2nd longest words" ... that implies to me that if your string was:

that cat in the hat was the next up at bat

Then the second longest words would be: cat, the, hat, was, bat

I assume you want the result list NOT to contains duplicates: correct ?

Member 10977819 8-Nov-14 7:43am

Hi Bill, maybe I left my msg little too late. I'm in NZ time zone so if you leave a msg, I'll be checking it about 9 hours later... Thanks and sorry for replying it late...

BillWoodruff 8-Nov-14 9:20am

fyi: I'm at GMT +7, so I'm five hours "before" you. I'm going to post some code to help you get started, leaving out parts of it for you to figure out.

Member 10977819 8-Nov-14 4:04am

Hi Bill, thanks again~ and sorry I was away... and yes, "apple" and "apple," are considered the same words with 5 characters. And yes, if it was "that cat in the hat was the next up at bat" then I want to see "cat, the, hat, was, bat" with NO duplicates. Thanks again and sorry for the late reply...

4 solutions

Solution 1

You can improve the second by adding more separators (e.g. punctuation) and by specifying http://msdn.microsoft.com/en-us/library/system.stringsplitoptions(v=vs.110).aspx[^]

Then iterate the results and compare the Lengths of each string.

Posted 7-Nov-14 18:16pm

PIEBALDconsult

Comments

Sergey Alexandrovich Kryukov 8-Nov-14 1:12am

This is not a good idea, because the number of potential delimiter is much greater. Please see my answer.
—SA

BillWoodruff 8-Nov-14 1:42am

Except: if the OP has a clear idea of which delimiters they want to deal with, then this is a very reasonable suggestion ... at this point where we are "in the dark fumbling with the elephant" trying to figure out if we are "wise men" :)

Sergey Alexandrovich Kryukov 8-Nov-14 1:48am

Well, more exactly, if the set of the delimiters is limited to some predefined set.
But the problem looks like an assignment, so it should be solved strictly.
—SA

PIEBALDconsult 8-Nov-14 9:48am

"But the problem looks like an assignment, so it should be solved " by the student, not us. Don't give a student a fish.

Sergey Alexandrovich Kryukov 8-Nov-14 21:38pm

I don't think I gave too much, but I agree with the idea: it's much better to teach how to fish.
—SA

Maciej Los 8-Nov-14 10:50am

Punctuation has matter!
+5!

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

BillWoodruff · Accepted Answer · 2014-11-08T03:50:00

One way to approach a problem like this is called "divide-and-conquer:" break the problem into functional chunks: implement, and test, one chunk at a time. I think you can deal with this problem by dividing it up into three tasks:

1. It's clear from the information we have now that you need to do some pre-processing of the string before you analyze which words are unique and "second longest." Multiple-white-space has to be changed to one white-space ... or ignored; and, punctuation, and other special characters, must be removed.

2. Then you want to eliminate duplicate words in the string.

3. Finally, you want to get the lengths of the cleaned-up unique words in the string, and get the words with length equal to the length of a second longest word in the string.

Note you could start with working on any of these tasks; you could create appropriate sample data to test with that was cleaned-up, or had duplicates removed, to use in tasks 2, 3, for example.

Let's focus on task 1:

While you could do some fancy stuff in Linq to handle multi-character and multi-white-space change to one white-space, I think simple may be better here; we'll use a StringBuilder for efficiency in dealing with characters.

You already know you need to have a loop and go through the whole string character by character.

C#

private string StripWords(string theString, bool doRemovePunctuation, params char[] otherCharsToRemove)
{
    StringBuilder sb = new StringBuilder();

    // keep track of whether the last space was white-space
    // note it may be white-space now because we changed
    // it to white-space in the code below
    bool currentCIsWhiteSpace = false, lastCIsWhiteSpace = false;

    char chr;

    foreach (var currentc in theString)
    {
        // can we take a short-cut here ?
        if (lastCIsWhiteSpace && char.IsLetterOrDigit(currentc))
        {
            // what do you need to update here
            // so that you continue the loop iteration ?
            //continue;
        }

        lastCIsWhiteSpace = currentCIsWhiteSpace;

        currentCIsWhiteSpace = Char.IsWhiteSpace(currentc);

        // if we are removing punctuation: replace with space
        // remove other optional chars: replace with space
        chr = currentc;

        if (currentCIsWhiteSpace
            || (doRemovePunctuation && Char.IsPunctuation(currentc))
            || othersCharsToRemove.Contains(currentc))
        {
            chr = ' ';
            currentCIsWhiteSpace = true;
        }

        sb.Append(chr);
    }

    return sb.ToString();
}

If we get this task right, then with a string like:

C#

string testString = @"I like <apples>. I treasure: mango, pineapple, lychee. I like rambutan, and green bananas; durian stinks";

And a call to:

C#

string cleanString = StripWords(testString, true,':','<','>');

We should get output like this:

"I like apples I treasure mango pineapple lychee I like rambutan and green bananas durian stinks"

Maciej Los · Accepted Answer · 2014-11-08T04:46:00

The discussion about the list of separators is still active. I agreee with BillWoodruff about the duplicates. As you can see apples word is iterated 3 times. In case you want to get third or fourth longest word, the result will be apple. Why? Have a look at the list of returned words:

1 - bananas
2 - apples 
3 - apples 
4 - apples 
5 - green 
6 - like 
7 - like 
8 - like 
9 - red 
10 - red 
11 - and 
12 - I 
13 - I 
14 - I

When we remove duplicated words, the result list should looks like:

1 - bananas
2 - apples
3 - green
4 - like
5 - red
6 - and
7 - I

And now the time for sample code. It uses Linq[^]:

C#

string st = "I like apples. I like red apples. I like red apples and green bananas.";
char[] sep = new char[]{'.',',',' '};
string secondLongestWord = (from words in st.Split(sep).Distinct().ToArray()
    orderby words.Length descending
    select words).Take(2).Last().ToString();

Console.WriteLine("Second longest word is: {0}" , secondLongestWord);

Result:

Second longest word is: apples

[EDIT]
Few words of explanation about the code (see comments).

C#

//get the array of non-duplicated words, splited by defined characters
(from words in st.Split(sep).Distinct().ToArray()
//order by the length of text
orderby words.Length descending
//list words, returns IOrderedEnumerable<String>
select words)
//get only 2 rows
.Take(2)
//get last row, in this case the second one;)
.Last()
//return string
.ToString()

For futher information, please see:
Take()[^]
Last()[^]

Final note: In a meanwhile i found another solution, using Regex class[^].

Using proper pattern[^] we are able to remove punctuation characters and numbers. Just replace from clause with:

C#

from words in Regex.Split(st, @"\W").Distinct().ToArray()

and remove this line:
C#

char[] sep = new char[]{'.',',',' '};

[EDIT 2]
Thanks to BillWoodruff[^] for valuable comment.
In case when there must be a list of "second-longest-words", the solution is:

C#

string st = "I like apples :) I like red apples :P I'd like to eat 1 red apple and 5 (five) yellow bananas.";

int secondvalue = (from words in Regex.Split(st, @"\W").Distinct().ToArray()
    orderby words.Length descending
    select words.Length).Take(2).Last();
Console.WriteLine("Second length of word is: {0}", secondvalue);

var qry = from words in Regex.Split(st, @"\W").Distinct().ToArray()
where words.Length == secondvalue
select words;
Console.WriteLine();
Console.WriteLine("List of words:");
foreach (string word in qry)
{
    Console.WriteLine("{0}", word);
}

I'd suggest to write extension method ;)
Extension Methods (C# Programming Guide)[^]
How to: Add Custom Methods for LINQ Queries[^]

Sergey Alexandrovich Kryukov · Accepted Answer · 2014-11-07T18:53:00

Solution 2

Use the following functions:
http://msdn.microsoft.com/en-us/library/system.char.isletter%28v=vs.110%29.aspx[^],
http://msdn.microsoft.com/en-us/library/0t641e58%28v=vs.110%29.aspx[^].

Everything else will be considered as word delimiters. How to consider digits, delimiters or parts of words, depends on required approach. For example, one can count digits as non-delimiters, but ignore all words containing at least one digit. Or something else.

—SA

Posted 7-Nov-14 18:53pm

Sergey Alexandrovich Kryukov

Updated 7-Nov-14 19:58pm

v3

Comments

BillWoodruff 8-Nov-14 1:38am

I think until the OP clarifies the use-cases they need to deal with, we are kind of guessing here in terms of what specific functions of the 'Char Class might be most useful ... of course, the OP may not have fully thought the use-cases through ... yet: nothing wrong with that; if we can help the OP elucidate the use-cases, I think we all win :) I've asked the OP to clarify.

Char.IsLetterOrDigit was the first thing sprang to my mind :)

If I'm going to write a function to strip/replace a bunch of chars in a string, I think I'll take the trouble to make it general-purpose, and handle cases like "<apple>" => "apple"

Sergey Alexandrovich Kryukov 8-Nov-14 1:51am

You see, even of OP clarifies the definition of "words" (I wouldn't hold my breath :-), this approach will work anyway. Don't you agree? I explained why using IsLetter and IsDigit separately, in the last paragraph.
Anyway, it was the good idea to ask for clarification. It just cannot change much...
—SA

BillWoodruff 8-Nov-14 1:55am

In your last paragraph: "For example, one can count the as non-delimiters" I think you accidentally left out some characters, or the CP editor stripped them out.

Sergey Alexandrovich Kryukov 8-Nov-14 1:59am

Typo, of course. Thank you very much; fixed.
—SA

Maciej Los 8-Nov-14 10:49am

Yeah, good point.
+5!

Sergey Alexandrovich Kryukov 8-Nov-14 20:41pm

Thank you, Maciej.
—SA

Manas Bhardwaj 8-Nov-14 11:18am

Yup 5!

Sergey Alexandrovich Kryukov 8-Nov-14 20:41pm

Thank you, Manas.
—SA

[no name] 8-Nov-14 17:54pm

"Parsing" language ....pay attention to white char and punctuation and more. 5 from me. Regards, Bruno

Sergey Alexandrovich Kryukov 8-Nov-14 20:41pm

In this case, it's all cover by the notion of "not letter and not digit".
Thank you, Bruno.
—SA

How to find the 2nd longest word(s) in the text using C#, WinForm

4 solutions

Solution 3

Solution 4

Solution 1

Solution 2

Add your solution here

Preview 0