How to find if all characters in a string are a number

Ever needed to find out whether all the characters in a string are numbers, so they can be converted to an int or validated for example? There are a couple of ways this can be achieved.

Perhaps the most obvious way is something like this

int someNumber;
if(int.TryParse("1234", out someNumber)) // or double.TryParse, for none whole numbers
	Console.WriteLine ("It is a number!");
else
	Console.WriteLine ("It's not a number");

Or you can do it the way I prefer if you don’t need to do anything specificity with the number.

string myString = "1234";
if(myString.All(s => Char.IsDigit(s)))
	Console.WriteLine ("It is a number!");
else
	Console.WriteLine ("It's not a number");