Identify if a string is a number

Question

If I have these strings:

1. \"abc\" = false

2. \"123\" = true

3. \"ab2\"

Answer 1

UPDATE of Kunal Noel Answer

stringTest.All(char.IsDigit);
// This returns true if all characters of the string are digits.

But, for this case we have that empty strings will pass that test, so, you can:

if (!string.IsNullOrEmpty(stringTest) && stringTest.All(char.IsDigit)){
   // Do your logic here
}