Check if a string has only blank spaces or zeros with C#

Question

I want to detect if an IBAN account has all digits at zero 0, for example

00 0000 000 00 0000000000.

So I build this regex pattern to check it:

^(0\s){0,25}$

The argument would be: Check if the input string has only blank spaces or zeros.

But this does not work. Any help? Thank you.

Answer 1

Here is a non-regex example.

string input = "00 0000 000 00 0000000000";

bool isNotAllZeros = input
    .Where(x => char.IsDigit(x))
    .Any(x => x != '0');

It says: "get me all the digits from the string, and see if there are any that are not '0'."

Another method (to avoid double-negatives), using All, which might make more sense when reading:

bool isAllZeros = input
    .Where(x => char.IsDigit(x))
    .All(x => x == '0');

This says "are all the digits in the input '0'?"