👩‍💻 判斷字串是否為數字

StringName.All(char.IsDigit);

using System;
using System.Linq;

public class IdentifyString
{
    public static void Main()
    {
      string number = "123456";
      if(number.All(char.IsDigit))
      {
          Console.WriteLine("The Given String is a Number.");
      }
      else
      {
          Console.WriteLine("The Given String is Not a Number.");
      }
    }
}

ref: C# 識別字串是否為數字 | D棧 - Delft Stack