Question

I have a list of post codes which should be excluded from my shipping methods.

Suppose I have to exclude Scilly Isles, Isle of Man and few others.

For the above 2 areas valid post codes are IM1-IM9, IM86, IM87, IM89. And if it is IM25 or IM85 it is invalid.

I have writtent following expression. But it is returning even it is IM25 or IM 85.

var regex = new Regex("(PO3[0-9]|PO4[0-1]|GY[1-9]|JE[1-5]|IM[1-9]|TR[1-9])");

If I am passing IM85, to my expression it should return false. for IM1-IM9,, IM86, IM87, IM89 it should return true.

Same with TR post codes also. TR1-TR27 is a valid post code. If I give TR28, it should return false.

I am using ‘|’ to seperate multiple patterns. Is that the right way of including multiple patterns in 1 expression.

Answer 1

I have changed my approach.

Instead of going for a regular expression which is becoming more complex, I am saving all the excluded outward codes of UK post codes.

And if any post code contains the particular outward code, excluding the post code from the list.
Outward codes are in this format

XX-YYY
XXX-YYY
XXXX-YYY

In all above formats, X represents outward code of an UK postcode.