How do I identify if a string is a number in C#?

Let us say our string is −

string str = "3456";

Now, to check whether the entered string is a number or not −

str.All(c => char.IsDigit(c))

The above returns true if the string is a number, else false.

Here is the complete code −

Example

 Live Demo

using System;
using System.Linq;

namespace Demo {
   public class MyApplication {
      public static void Main(string[] args) {
         string str = "3456";
         // checking if string is a number or not
         Console.WriteLine(str.All(c => char.IsDigit(c)));
      }
   }
}

Output

True