csharp how do you check if a string contains only digits

Code Example - csharp how do you check if a string contains only digits

                
                        if (str.All(char.IsDigit)) {
  Console.WriteLine("This string only contains numbers");
}
                    
                
 

csharp check if string is all numbers

                        
                                if (str.All(char.IsDigit)) {
  // String only contains numbers
}