Btukfyl

I got a code which finds a word in a line that has at least 3 different vowels. The problem is I don't know why it goes out of bounds.

static string findword(string e)

{

    char vowels = { 'a', 'e', 'i', 'o', 'u' };

    char sk = { ' ', '.', ',', '!', '?', ':', ';', '(', ')', 't' };

     string word= "";

    string parts = e.Split(sk, StringSplitOptions.RemoveEmptyEntries);

        for (int i = 0; i < e.Length; i++)

        {

            if (parts[i].IndexOf(vowels[i]) >= 3)

            {

                word = parts[i];

            }

        }

    return word;

}

So for e = "I was going home today" it should return "today".

Here's my version:

        var e = "I was going home today";



        char vowels = { 'a', 'e', 'i', 'o', 'u' };

        char sk = { ' ', '.', ',', '!', '?', ':', ';', '(', ')', 't' };

        string word = "";

        string parts = e.Split(sk, StringSplitOptions.RemoveEmptyEntries);

        var mostVowels = 0;



        for (int i = 0; i < parts.Length; i++)

        {

            var part = parts[i];

            var numberOfVowels = 0;

            foreach (var vowel in vowels)

            {

                if (part.Contains(vowel)) numberOfVowels++;

            }



            if (mostVowels < numberOfVowels)

            {

                mostVowels = i;

                word = part;

            }

        }

        return(word);

It loops through the parts, then another loop checks if the part contains each vowel. Then it checks whether this word is better than the previous best.

Note that this returns 'going' because it was the first word with two vowels.

Note also that I've used 'foreach' instead of a normal for loop, this helps to avoid many common mistakes.

This code could be better, as it only looks for each vowel once. A word like 'Aardvark' would only score 1. No doubt there's a really concise way to do this with LINQ and Regular Expressions, but hopefully this will help you see where you were going wrong with your loops and arrays.

EDIT: Here's a regex & LINQ version for you:

    var r = new Regex("(a|e|i|o|u)");

    var mostVowels = parts.Max(y => r.Matches(y).Count);

    var result = parts.First(x => r.Matches(x).Count == mostVowels);

The Regex is a helper for finding vowels. The first query works out the number of vowels in each word and returns the maximum. The second finds the first word with that many vowels.

i goes from 0 to e.Length - 1, but you use it to access the array parts, which might have different length or might not.

When the question is

why it goes out of bounds

(The question title suggest a totally different question problem than the context, it would be nice to fix the title.)

Then the answer is very simple. It is because of this:

Reason 1:

for (int i = 0; i < e.Length; i++)

Should be:

for (int i = 0; i < parths.Length; i++)

Reason 2:

if (parts[i].IndexOf(vowels[i]) >= 3)

Should be:

if (CountVowels(parts[i]) >= 3)

Unfortunately the CountVowels function is out of scope for this question and since it sound like a homework you need to create the function CountVowels by your self.