Question

I tried to create a Regular expression. To validate a city that must start with “apo” or “fpo”.

Without or with space and dot in between “a.p.o” or “Apo”, “APO”. I tried this:

^(APO)?|(apo)?\s*\.\w

but it won’t work for me.

Answer 1

C# .NET

Use IsMatch with RegexOptions.IgnoreCase. The regex:

@"^[af][ .]?p[ .]?o"

Objective-C

You can use - (NSTextCheckingResult *)firstMatchInString:(NSString *)string options:(NSMatchingOptions)options range:(NSRange)range method to check for the first match. If not found then failure. The regex:

@"^(?i)[af][ .]?p[ .]?o"