Find and extract a number from a string

Question

I have a requirement to find and extract a number contained within a string.

For example, from these strings:

string test = \"1 test\"
string test1 =         


        

Answer 1

if the number has a decimal points, you can use below

using System;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            //Your code goes here
            Console.WriteLine(Regex.Match("anything 876.8 anything", @"\d+\.*\d*").Value);
            Console.WriteLine(Regex.Match("anything 876 anything", @"\d+\.*\d*").Value);
            Console.WriteLine(Regex.Match("$876435", @"\d+\.*\d*").Value);
            Console.WriteLine(Regex.Match("$876.435", @"\d+\.*\d*").Value);
        }
    }
}

results :

"anything 876.8 anything" ==> 876.8

"anything 876 anything" ==> 876

"$876435" ==> 876435

"$876.435" ==> 876.435

Sample : https://dotnetfiddle.net/IrtqVt

Answer 2

  string verificationCode ="dmdsnjds5344gfgk65585";
            string code = "";
            Regex r1 = new Regex("\\d+");
          Match m1 = r1.Match(verificationCode);
           while (m1.Success)
            {
                code += m1.Value;
                m1 = m1.NextMatch();
            }

Answer 3

Here's a Linq version:

string s = "123iuow45ss";
var getNumbers = (from t in s
                  where char.IsDigit(t)
                  select t).ToArray();
Console.WriteLine(new string(getNumbers));

Answer 4

Here's how I cleanse phone numbers to get the digits only:

string numericPhone = new String(phone.Where(Char.IsDigit).ToArray());

Answer 5

static string GetdigitFromString(string str)
    {
        char[] refArray = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
        char[] inputArray = str.ToCharArray();
        string ext = string.Empty;
        foreach (char item in inputArray)
        {
            if (refArray.Contains(item))
            {
                ext += item.ToString();
            }
        }
        return ext;
    }

Answer 6

use regular expression ...

Regex re = new Regex(@"\d+");
Match m = re.Match("test 66");

if (m.Success)
{
    Console.WriteLine(string.Format("RegEx found " + m.Value + " at position " + m.Index.ToString()));
}
else
{
    Console.WriteLine("You didn't enter a string containing a number!");
}