xxxxxxxxxx
if (textVar.All(c => Char.IsLetterOrDigit(c))) {
// String contains only letters & numbers
}
xxxxxxxxxx
using System;
using System.Text.RegularExpressions;
class Program
{
static void Main()
{
string input = "12345";
bool containsOnlyNumbers = Regex.IsMatch(input, @"^[0-9]+$");
Console.WriteLine(containsOnlyNumbers); // Outputs: True
}
}
xxxxxxxxxx
if (str.All(char.IsDigit)) {
Console.WriteLine("This string only contains numbers");
}