Removing any element other than numbers from character array

Question

I have a multi line string text that has in each line a phone number joined by some text or spacial characters(characters not in English) so I want to check the text line by line and for each line extract the phone number and keep it in a rich text box I faced one problem and that is how to Remove any element other than numbers from character array .. any help !!

using(StringReader reader=new StringReader(richTextBox1.Text))
            {
                string line = string.Empty;
                do
                {
                    line = reader.ReadLine();
                    if (line != null)
                    {
                        // Checking if the line contains things other than letters
                        char[] buffer = line.Replace(" ", string.Empty).ToCharArray();
                        for (int i = 0; i < buffer.Length; i++)
                        {
                            if (!char.IsNumber(buffer[i]))
                            {
                                // Delete any letters or spacial characters
                            }
                        }

                        Regex rx = new Regex("^[730-9]{9}$");
                        if (rx.IsMatch(line))
                        {
                            richTextBox2.Text+=line;
                        }

                    }
                } while (line != null);

            }}

Don't use a character array. Iterate through the string. Neither a string nor an array allows removal of elements, so build a *new* string instead. Start with an empty string variable, and add to it each character that you wish to keep. — 15ee8f99-57ff-4f92-890c-b56153, Jun 30 '17 at 16:19
[This](https://stackoverflow.com/a/3210462/2457029) is what you are looking for — maccettura, Jun 30 '17 at 16:20

Yurii N. · Accepted Answer · 2017-06-30T16:26:41.830

1

Char.IsDigit should help:

string lineWithoutNumbers = line.Where(x => Char.IsDigit(x));

In your case, something like this:

using(StringReader reader=new StringReader(richTextBox1.Text))
        {
            string line = string.Empty;
            do
            {
                line = reader.ReadLine();
                if (line != null)
                {
                    // Checking if the line contains things other than letters
                    line = new String(line.Where(x => Char.IsDigit(x)).ToArray()); //here, we remove all non-digits from the line variable

                    Regex rx = new Regex("^[730-9]{9}$");
                    if (rx.IsMatch(line))
                    {
                        richTextBox2.Text+=line;
                    }

                }
            } while (line != null);

        }}

edited Jun 30 '17 at 16:26

answered Jun 30 '17 at 16:22

Yurii N.

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I want to keep the numbers – Mohammed Shfq Jun 30 '17 at 16:24
Might need https://stackoverflow.com/questions/11654190/ienumerablechar-to-string – user6144226 Jun 30 '17 at 16:24
@MohammedShfq so, you will, it returns only numbers – Yurii N. Jun 30 '17 at 16:25
@MohammedShfq try now. – Yurii N. Jun 30 '17 at 16:36

Removing any element other than numbers from character array

1 Answers1