how to check if my string contain text?

Question

if i have this string:

12345 = true

123a45 = false

abcde = false

how to do it in C#?

Answer 1

Regex.IsMatch(sinput,@"\d+"); 

to match a string containing just digits. If you forgot an optional digit in the question, use this:

Regex.IsMatch("+12345", @"[+-]?\d+");

Answer 2

If you want to avoid RegEx, then you can use the built-in char methods:

bool allDigits = s.All(c => char.IsDigit(c));