Regular Expression splitting up of NSString - iOS

Question

Split String using Regular Expression in iOS

I have solved this problem using loops, however would like a cleaner answer and I hope a reg exe guru can help me out.

Answer 1

Here's a regex that should work:

       ^             //start of line
       (             //first capture group
            [\d]+    //one or more digits
       )             //end of first capture group 

       (?:           //start of optional non-capturing group
              \s?    //optional whitespace
            (        //second capture group
              [ab]   //character class - a or b
            )        //end of second capture group 
       )?            //end of optional non-capturing group 

       \s            //whitespace

       (             //third capture group
            (?:      //non-capturing group
      Mr|Mrs|Mister  //title alternation
            )         
            \s       //whitespace
            [\w/]+   //1 or more word characters or "/"
       |             //alternation 
            [\w/]+   //1 or more word characters or "/"
       )             //end of third capture group 

       (?:           //start of optional non-capturing group  
            \s       //whitespace
            (        //fourth capture group
            .*       //0 or more of any character
            )        //end of fourth capture group
        )?           //end of optional non-capturing group
       $             //end of line

Construct your regex. We have to escape the escapes to retain them in an NSString:

NSString* regexString =
@"^([\\d]+(?:\\s?[ab])?)\\s((?:Mr|Ms|Mrs|Mister)\\s[\\w/]+|[\\w/]+)(?:\\s(.*))?$";

NSRegularExpression *regex =
[NSRegularExpression regularExpressionWithPattern:regexString
                     options:NSRegularExpressionCaseInsensitive
                     error:nil];

Make a test array:

NSArray* testArray = @[
                        @"123a mr who here are some words"
                       ,@"124 b mrs jones n/p"
                       ,@"654 Mr Foo"
                       ,@"123 Jones n/p"
                       ,@"345 n/p"
                       ,@"345"
                       ,@"nothing here"
                       ];

Process the test array:

for (NSString* string in testArray) {
    NSLog(@" ");
    NSLog(@"input: '%@'",string);

    NSRange range = NSMakeRange(0,string.length);
    if ([regex numberOfMatchesInString:string options:0 range:range] == 1) {
        NSString* body = [regex stringByReplacingMatchesInString:string
                                           options:0
                                             range:range
                                      withTemplate:@"$1\n$2\n$3"];


        NSArray* result = [body componentsSeparatedByString:@"\n"];
        NSString* one = result[0];
        NSString* two = result[1];
        NSString* three = result[2];
        NSLog(@"one:   '%@'",one);
        NSLog(@"two:   '%@'",two);
        NSLog(@"three: '%@'",three);
    } else {
        NSLog(@"no match");
    }
}

Output:

    input: '123a mr who here are some words'
    one:   '123a'
    two:   'mr who'
    three: 'here are some words'

    input: '124 b mrs jones n/p'
    one:   '124b'
    two:   'mrs jones'
    three: 'n/p'

    input: '654 Mr Foo'
    one:   '654'
    two:   'Mr Foo'
    three: ''

    input: '123 Jones n/p'
    one:   '123'
    two:   'Jones'
    three: 'n/p'

    input: '345 n/p'
    one:   '345'
    two:   'n/p'
    three: ''

    input: '345'
    no match

    input: 'nothing here'
    no match