Get specific numbers from string

Question

In my current project I have to work alot with substring and I'm wondering if there is an easier way to get out numbers from a string.

Example: I have a string like this: 12 text text 7 text

I want to be available to get out first number set or second number set. So if I ask for number set 1 I will get 12 in return and if I ask for number set 2 I will get 7 in return.

Thanks!

Answer 1

This will create an array of integers from the string:

using System.Linq;
using System.Text.RegularExpressions;

class Program {
    static void Main() {
        string text = "12 text text 7 text";
        int[] numbers = (from Match m in Regex.Matches(text, @"\d+") select int.Parse(m.Value)).ToArray();
    }
}

Answer 2

Try using regular expressions, you can match [0-9]+ which will match any run of numerals within your string. The C# code to use this regex is roughly as follows:

Match match = Regex.Match(input, "[0-9]+", RegexOptions.IgnoreCase);

// Here we check the Match instance.
if (match.Success)
{
    // here you get the first match
    string value = match.Groups[1].Value;
}

You will of course still have to parse the returned strings.

Answer 3

Looks like a good match for Regex.

The basic regular expression would be \d+ to match on (one or more digits).

You would iterate through the Matches collection returned from Regex.Matches and parse each returned match in turn.

var matches = Regex.Matches(input, "\d+");

foreach(var match in matches)
{
    myIntList.Add(int.Parse(match.Value));
}