How to find and extract only number from string in C#?

You can extract the number from a string using Regex, here is the regex that should work

Method first:

var NumberFromString= string.Join(string.Empty, Regex.Matches(StringWithNumber, @"\d+").OfType<Match>().Select(m => m.Value));

Input: " 121 testing"

Output: "121"

Second Method:

string StringWithNumbers= "121 - Testing";

var data = Regex.Match(StringWithNumbers, @"\d+").Value;

Console.WriteLine(data);

Third method:

Now it may be possible that your string may have a number like this "121/1 Testing answer", which may contain special characters also, so in that case, you would need a regex like below to remove special characters (-,/)

   Regex rgx = new Regex("[^0-9-/]");
  
   var Number = rgx.Replace("121/1 Testing String", "");  //121/1
   var remainingString = Model.Street.Replace(Number, "");   

In this way, you can do this using Regex and change it according to your need.

Fourth way using char.IsDigit

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

Thanks.

You can also get only numbers using char.IsDigit without regex.

string a = "hello1234World";
string b = string.Empty;
int val;

for (int i=0; i< a.Length; i++)
{
    if (Char.IsDigit(a[i]))
        b += a[i];
}

if (b.Length>0)
    val = int.Parse(b);

Console.WriteLine(val);

Thanks