Question

I need a RegEx to check if an item order count is either 0 or between 2500 and 999999. Is this even possible to do?

Example:
You can either order 0 (no items) or you have to make an order of 2500 or more items.

Update:
This need to be a RegEx because it will be used in a validation attribute in MVC.

[RegularExpression(@"SomeRegExpression", ErrorMessage = "Min order error")]

Answer 1

If it has to be a regex:

^(?:0|\d{5,6}|2[5-9]\d\d|[3-9]\d\d\d)$

Explanation:

^                # Start of string
(?:              # Either match...
 0               # 0
|                # or
 \d{5,6}         # a five- or six-digit number
|                # or
 2[5-9]\d\d      # 2500-2999
|                # or
 [3-9]\d\d\d     # 3000-9999
)                # End of alternation
$                # End of string