Identify if a string is a number

Question

If I have these strings:

1. \"abc\" = false

2. \"123\" = true

3. \"ab2\"

Answer 1

This will return true if input is all numbers. Don't know if it's any better than TryParse, but it will work.

Regex.IsMatch(input, @"^\d+$")

If you just want to know if it has one or more numbers mixed in with characters, leave off the ^ + and $.

Regex.IsMatch(input, @"\d")

Edit: Actually I think it is better than TryParse because a very long string could potentially overflow TryParse.