Regular expression to check if string contains only zeros

Question

I need to validate an Amount field, which should not be Zero amount. For eg. it CANNOT be 0000,0.00,000.000,0 BUT it CAN be 0.0001, 1.000,1.00,1234.00 etc values.

Tried @"[^1-9]+" and @"0+((\.0+)" But they invalidate every value which contains a zero.

Answer 1

I don´t see why you need a regex, simply convert the string to a number and check if that is 0:

decimal actNumber;
if(decimal.TryParse(myAmount, out actNumber) && actNumber > 0) 
{ /* ... */ }

Thus you can also use the actual number afterwards.

Answer 2

If you want a regular expression to check for strings containing only one character, you can just specify that the character be located at the beginning, end, and everywhere in between. Here is an example of how to do so for the digit 0:

regexp '^0+$'

If you are worried about the value containing non-zero digits, you can ensure that no such characters are present using:

regexp '^[^1-9]+$'