How can I parse the int from a String in C#?

Question

I have a string that contains an int. How can I parse the int in C#?

Suppose I have the following strings, which contains an integer:

    15 person 
    person 15
    person15
    15person

How can I track them, or return null if no integer is found in the string?

Answer 1

You can remove all non-digits, and parse the string if there is anything left:

str = Regex.Replace(str, "\D+", String.Empty);
if (str.Length > 0) {
  int value = Int32.Parse(str);
  // here you can use the value
}