如何匹配字母和数字组合的单词，但避免只包含数字的单词

Question

I need to create a RegEx that can get me the PO BOX full information from a string, I figured that I need to get and then everything else up to the point where a full string of numbers is found (the po box number is ok, after that , only if a word is a combination of numbers and letters is ok to match, if the whole word is made out of numbers then it should stop there ie

From the following string:

"Po Box 321 Stn Commerce Court 123 Sample St"   

I need to get everything before 123 Sample St , like this:

"Po Box 321 Stn Commerce Court "

From the following string:

"PO Box 456 Stn 1st Can Place" 

I need to get everything because there is no word made out of only numbers after the PO Box number

So far I achieve to get the first case working, but I haven't yet find an expression that works for both strings,

My attempt:

Regex.Match(txtString.Text, @"PO BOX [0-9]+([\s\w][^0-9]*|\s[a-zA-Z0-9]\s)", RegexOptions.IgnoreCase)

Thank you

Answer 1

You can use a positive look ahead :

PO BOX [0-9]+.*(?= \d+|$)

See demo https://regex101.com/r/bK7nY2/1

Or use a negative look ahead :

PO BOX [0-9]+((?!\d+ ).)*

Demo https://regex101.com/r/bK7nY2/3