how to extract words from the list using regex?

Question

User-1404113929 posted

hi,

I have list of string values like

helloworld aaa

hello asdasd

hellotest adfasasd

test hello adasd

helloworld adasd

when i search for hello in that list i want result like

helloworld

hello

hellotest

hello

helloworld.

Thanks,

Murali

Answer 1

User283571144 posted

Hi balu.devara,

how to extract words from the list using regex?

According to your description, I suggest you could use String.Split method split the string, firstly.

Then you could use Regex.IsMatch method to get the result.

Regax:

^[a-zA-Z]*hello[a-zA-Z]*$

Pattern	Description
^	Begin the match at the beginning of the line.
[a-zA-Z]	Match a single alphabetic character (a through z or A through Z)
*	Match 0-MAX characters.
hello	Match hello
[a-zA-Z]	Match a single alphabetic character (a through z or A through Z)
*	Match 0-MAX characters.
$	End the match at the end of the line

More details, you could refer to follow codes and link:

 static void Main(string[] args)
        {
            List<string> l1 = new List<string>();
            List<string> result = new List<string>();
            l1.Add("helloworld aaa");
            l1.Add("hello asdasd");
            l1.Add("hellotest adfasasd");
            l1.Add("test hello adasd");
            l1.Add("helloworld adasd");

            Regex rgx = new Regex(@"^[a-zA-Z]*hello[a-zA-Z]*$");
            foreach (string item in l1)
            {
                string[] temp = item.Split(' ');
                for (int i = 0; i < temp.Length; i++)
                {
                    if (rgx.IsMatch(temp[i]))
                    {
                    result.Add(temp[i]);
                    }    
                }
            }
            foreach (string item in result)
            {
                Console.WriteLine(item);
            }
            Console.Read();
        }

Regex.IsMatch:

https://msdn.microsoft.com/en-us/library/3y21t6y4(v=vs.110).aspx

Best Regards,

Brando

Answer 2

User-1404113929 posted

hi,

thanks for your replay , i found another way to solve the issue.

thanks,

murali

Answer 3

User-1404113929 posted

hi,

i used bellow code , it works fine.

 var searchKeysList = new Collection<string>();
            var cacheKey = Common.Constants.CacheKeys.ActivitySearchKeys;
            Collection<string> resultKeysList = new Collection<string>();
            var regx = new System.Text.RegularExpressions.Regex(string.Format(@"(?i)\b\w*{0}\w*", searchTerm));
            if (!this.CacheService.IsExists(cacheKey))
            {
                searchKeysList = this.ActivityDAO.GetSearchKeys();
                this.CacheService.AddDataToCache(cacheKey, searchKeysList);
            }
            else
            {
                searchKeysList = this.CacheService.GetDataFromCache<Collection<string>>(cacheKey);
            }

            var filterKeysList = searchKeysList.ToList().Where(x => x.IndexOf(searchTerm, StringComparison.InvariantCultureIgnoreCase) >= 0).ToList();

            foreach (var filterKey in filterKeysList)
            {
                foreach (Match m in regx.Matches(filterKey))
                {
                    resultKeysList.Add(m.Value);
                }
            }

            resultKeysList = resultKeysList.GroupBy(x => x).Select(g => g.Key).OrderBy(x => x).ToCollection();