Fastest way to check if string contains only digits

Question

I know a few ways how to check this. regex,int.parse,tryparse,looping.

can anyone tell me what is the fastest way to check?

the nee

Answer 1

Probably the fastest way is:

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

Note: it will return True in case your string is empty which is incorrect (if you not considering empty as valid number/digit )