Checking and editing NSMutableString

Question

I get results in the following format:

NSString *placeResult = @"111 Main Street, Cupertino, CA"

or sometimes the result contains the name of a place:

NSString *placeResult = @"Starbucks, 222 Main Street, Cupertino, CA"

I need to check if the text before the first comma is numeric or alphabets. If the characters are alphabets, then from the NSMutableString I need to remove the first comma and all the alphabets before it, and store the only the alphabets in a variable. So the text in the second example will look like:

@"222 Main Street, Cupertino, CA"

How can I accomplish this with NSRegularExpression, NSTextCheckingResult, and NSMutableString?

I'm thinking:

 NSString *str= (NSString *)location.address;
 NSMutableString *muteStr;
 muteStr = [NSMutableString stringWithString:str];

    NSArray *matches = [detector matchesInString:muteStr options:0 range:NSMakeRange(0, muteStr.length)];

    for (NSTextCheckingResult *match in matches)
    {
        if (match.resultType == NSTextCheckingTypeAddress)
        {
            NSDictionary *data = [match addressComponents];
            NSString *name = data[NSTextCheckingNameKey];
            if (!name && match.range.location > 0)
            {
                NSRegularExpression *scan = [NSRegularExpression regularExpressionWithPattern:@"(?= )" options:0 error:NULL];  
//******I'm not sure if I have regularExpressionWithPattern correct?

                NSTextCheckingResult *result = [scan firstMatchInString:@"," options:0 range:NSMakeRange(0, name.length)];

Not sure what to do from here or even if it's the right approach?

Again, I need to check if the text before the first comma is numeric or alphabets. If the text/characters are alphabets, then from the NSMutableString I need to remove the first comma and all the alphabets before it, and store the only the alphabets in a variable. If the characters are numeric, I need to leave the NSMutableString as is.

Answer 1

I would choose another approach:

NSString *placeResult = @"Starbucks, 222 Main Street, Cupertino, CA";
// Split the NSString into an NSArray out of parts of the NSString
NSArray *parts = [placeResult componentsSeparatedByString:@","];
// This NSMutableString will store our edited string
NSMutableString *result = [[NSMutableString alloc] init];
// If there are only 3 NSStrings in parts it is only `Address`, `City` and `State`
// so we can use it as is
if (parts.count == 3)
    [result appendString:placeResult];
// If there are 4 NSStrings in parts there is something in front of we don't need,
// so we need to cut it off
else if (parts.count == 4) {
    // We start at `index 1` because at `index 0` is the element we don't want
    int startIndex = 1;
    // Here we append the first part and after that increment our index
    [result appendFormat:@"%@", parts[startIndex++]];
    // We loop through the NSArray starting at `index 2`, our next element
    for (; startIndex < parts.count; startIndex++)
        // We append our new element with a comma in front of it
        // Note that the string we append still starts with a space so we don't insert one here
        [result appendFormat:@",%@",parts[startIndex]];
    // Now our string is completely stored in `result`. 
    // What we need to do now is cut off the first space which was included 
    // when we inserted the first element before the loop.
    // I mean this space: @"Starbucks, 222 Main Street, Cupertino, CA";
    //                                ↑
    // Our NSString usually does always has a space in front, so this if-clause is a little superfluous but in case you get a string without a space after every comma this cuts off your first letter 
    if ([[result substringWithRange:NSMakeRange(0, 1)] isEqualToString:@" "])
        // Delete the first character which definitely is a space
        [result deleteCharactersInRange:NSMakeRange(0, 1)];
}
// I'm pretty sure what we do here ;)
NSLog(@"%@", result);

Output:

for @"111 Main Street, Cupertino, CA":

111 Main Street, Cupertino, CA

for @"Starbucks, 222 Main Street, Cupertino, CA":

222 Main Street, Cupertino, CA

Edit: This code does exactly what you want ;)