How can I check if a string is a number?

Question

I\'d like to know on C# how to check if a string is a number (and just a number).

Example :

141241   Yes
232a23   No
12412a   No

an

Answer 1

If you want to validate if each character is a digit and also return the character that is not a digit as part of the error message validation, then you can loop through each char.

string num = "123x";

foreach (char c in num.ToArray())
{
    if (!Char.IsDigit(c))
    {
        Console.WriteLine("character " + c + " is not a number");
        return;
    }
}