Question

We are using a RegEx Validator to validate an input from a textbox.

The current RegEx expression checks if the current number is between the range of 1 – 999.

We just inherited this code and we need to change the range from 999 to just 365. In short, we need to write a regex to check if the input is between 1 – 365.

Of course, we can just use a RangeValidator or a custom validator. But we don’t want to do that because we don’t want to introduce a “significant” change.

Thanks!

EDIT:

We should also catch this following patterns:
001 for 1
019 for 19

Answer 1

Using regular expressions is certainly not the best way to validate integer ranges, but here you go:

 ^([1-9][0-9]?|[12][0-9][0-9]|3[0-5][0-9]|36[0-5])$

[1-9][0-9]?     matches    1 -  99
[12][0-9][0-9]  matches  100 - 299
3[0-5][0-9]     matches  300 - 359
36[0-5]         matches  360 - 365

EDIT: With leading zeros (also matches strings like 00000000321):

 ^0*([1-9][0-9]?|[12][0-9][0-9]|3[0-5][0-9]|36[0-5])$