CODEWITHSUNDEEP
c#stringmatching
PhilJ
PhilJ

Reputation: 3

C# Need Help Finding matching word in input sentence

Okay, so I'm having trouble. I have a form that has three textboxes and a button, and in the first textbox (textBox1), the user inputs a sentence. In the next textbox (textBox3), the user inputs a word. Then the user clicks a button, and the third textbox (textBox2) checks to see if the word that is input matches a word in the sentence. I can't use any kind of "shortcuts", I can only go about it the long way (no .Compare or anything like that). Here's what I have so far:

 private void button1_Click(object sender, EventArgs e)
  {



        string inSentence = textBox1.Text.ToUpper();

        string txtB2 = textBox3.Text.ToUpper();

        string[] inWord;

        inWord = inSentence.Split(' ');

        int wordCount = inWord.Length;

        for (int i = 0; i < wordCount; i++)
        {
            if (txtB2 == inWord[i])
            {
                textBox2.Text = "Yes";
            }
            else
                textBox2.Text = "No";
        }

  }

The problem I'm having is that, say if I type "hi its me" in the first box, the only word that will match is "me". It only matches the last word. It's not matching everything.

Again, I can only go about it in a way sort of like this. I just would like to know where I'm going wrong, and why. If anyone can help me, it would be much appreciated.

I've also tried using this

  foreach (string n in inWord)
        {
            textBox2.Text = inWord + " ";
            for (int i = 0; i < wordCount; i++)
            {

                if (txtB2 == n)
                {
                    textBox2.Text = "Yes " + n;
                }
                else
                    textBox2.Text = "No " + n;
            }
        }

And am getting the same problem (I added the "n" to the text output to check what word it will be on and it's always on "ME" when I type in "hi its me").

Upvotes: 0

Views: 1626

Answers (6)

LSU.Net
LSU.Net

Reputation: 849

Without using regular expressions or IndexOf, and assuming you must use the very inefficient method of iterating through each word expressed below, you need to break execution of the loop upon finding a match. You should use a while construct rather than a for loop to accomplish this.

bool found = false;
int i = 0;
while (!found && i < wordCount)
{
    if (txtB2 == inWord[i])
    {
        textBox2.Text = "Yes";
        found = true;
    }
    else
        textBox2.Text = "No";

    i++;
}

Upvotes: 0

Krikor Ailanjian
Krikor Ailanjian

Reputation: 1852

What you are doing is looping through the entire sentence everytime. You check every word including the last one and the textBox2.Text is being changed at each word. What you see is the result at the last word.

    textBox2.Text == "No"; // Initially set the text to "No"
    for (int i = 0; i < wordCount; i++)
    {
        if (txtB2 == inWord[i])
        {
            textBox2.Text = "Yes"; // If a matching word is found change text to yes
            break;
        }
    }

If you want to use a foreach, you can leave out the other for loop inside like so:

textBox2.Text = "No";
foreach(string word in inWord)
{
    if(txtB2 == word)
        textBox2.Text = "Yes";
}

The foreach works by looping through inWord and putting the value of the current element in word

Upvotes: 0

Colin
Colin

Reputation: 4135

If you're wanting a practical way to go about the problem, there's this:

var inSentence = textBox1.Text;
var wordToFind = textBox3.Text;

var wordFound = Regex.IsMatch(@"\b" + inSentence + @"\b", wordToFind, RegexOptions.IgnoreCase);

If this is a contrived school assignment, then 1. your teacher should probably come up with a better exercise and 2. you really need to be doing the work yourself.

Upvotes: 0

user272671
user272671

Reputation: 657

If the only restriction is that you not use regular expressions, then you can do something like this

   var wordArray =  textBox1.Text.ToUpper().Split(" ");
    var response = wordArray.Where(x=> x.Trim().Equals(textbox2Input.ToUpper());
//the base implementation of the equals method on strings is enough

if(response.Any())
        textbox3.Text ="Yes";
    else 
    textbox3.Text="NO"

Upvotes: 0

Niclas
Niclas

Reputation: 1406

Try a regExp 

string text = "Your sentence";
string pat = "[^\s]word[$\s]"; //[rowstart or whitespace]word[rowend or whitespace]
Regex r = new Regex(pat, RegexOptions.IgnoreCase);
Match m = r.Match(text);
if(m.Success) {
   // The sentence contains the word
}

Upvotes: 0

rogi1609
rogi1609

Reputation: 438

Problem: The "problem" in your code is that always every word is checked. When a match was found, the loop is not stopped.

Solution: add a return; (or break) statement in your if statement after setting the textbox to "yes"

Upvotes: 1

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