Replace characters (unique then wildcard value) in a string with other characters

Question

I have an NSString, let's say "H,L,K,P" how can I detect a specific character than then a wild-car character... for example, checking for ",*" would return ",L" ",K" and ",P" because they all have the specific "," and then they all have a character after them. Then I want to replace that string with itself plus a "period" appended to it.

So "H,L,K,P" would become "H,L.,K.,P."

Answer 1

Use a regular expression. The search pattern would be:

,(.)

the replacement pattern would be:

,$1.

Sample code:

NSString *string = @"H,L,K,P";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@",(.)"
                                    options:0
                                    error:&error];
NSString *modifiedString = [regex stringByReplacingMatchesInString:string
                                    options:0
                                    range:NSMakeRange(0, [string length])
                                    withTemplate:@",$1."];