Question

I have a string as listed below.

string sample = ” class0 .calss1 .class2 .class3.class4 .class5 class6 .class7″;

I need to create a list of WORDS from this sample string.

A WORD is a string that starts with a period and ends with:

1. a space or
2. another period or
3. end of string

Note: The key point here is – the splitting is based on two criteria – a period and a blank space

I have following program. It works fine. However, is there a simpler/more efficient/concise approach using LINQ or Regular Expressions?

CODE

        List<string> wordsCollection = new List<string>();
        string sample = " class0 .calss1 .class2 .class3.class4  .class5 class6 .class7";

        string word = null;

        int stringLength = sample.Length;
        int currentCount = 0;

        if (stringLength > 0)
        {
            foreach (Char c in sample)
            {

                currentCount++;
                if (String.IsNullOrEmpty(word))
                {
                    if (c == '.')
                    {
                        word = Convert.ToString(c);
                    }
                }
                else
                {

                    if (c == ' ')
                    {
                        //End Criteria Reached
                        word = word + Convert.ToString(c);
                        wordsCollection.Add(word);
                        word = String.Empty;
                    }
                    else if (c == '.')
                    {
                        //End Criteria Reached
                        wordsCollection.Add(word);
                        word = Convert.ToString(c);
                    }
                    else
                    {
                        word = word + Convert.ToString(c);
                        if (stringLength == currentCount)
                        {
                            wordsCollection.Add(word);
                        }
                    }
                }

            }
        }

RESULT

        foreach (string wordItem in wordsCollection)
        {
            Console.WriteLine(wordItem);

        }

Reference:

1. Splitting up a string, based on predicate
2. Is there a better way to get sub-sequences where each item matches a predicate?
3. Linq based generic alternate to Predicate<T>?

Answer 1

You can do this with a regular expression.

Code

Regex regex = new Regex(@"\.[^ .]+");
var matches = regex.Matches(sample);
string[] result = matches.Cast<Match>().Select(x => x.Value).ToArray();

See it working online: ideone

Result

.calss1
.class2
.class3
.class4
.class5
.class7

Explanation of Regular Expression

\.      Match a dot
[^. ]+  Negative character class - anything apart from space or dot (at least one)

Related

• Character Classes or Character Sets