NSString remove duplicated substrings

Question

How can I remove duplicated substings from string? For ex. I have: aaa,bbb,ttt,bbb,rrr. And in result I want to have aaa,bbb,ttt,rrr (deleted duplicated bbb). I hope for your help. Thanks.

score 3 · Answer 1 · answered Aug 22 '13 at 10:47

You can do it like this:

NSMutableSet *seen = [NSMutableSet set];
NSMutableString *buf = [NSMutableString string];
for (NSString *s in [str componentsSeparatedByString:@","]) {
    if (![seen containsObject:s]) {
         [seen add:s];
         [buf appendFormat:@",%@", s];
    }
}
NSString *res = [buf length] ? [buf substringFromIndex:1] : @"";

keen · Accepted Answer · 2013-08-23T12:20:29.140

0

Do it in three steps

1) NSArray *items = [theString componentsSeparatedByString:@","];

2) remove duplicate element from array

    NSArray* array =  [NSArray arrayWithObjects:@"test1", @"test2", @"test1", @"test2",@"test4",   nil];

    NSArray* filteredArray = [[NSArray alloc] init];
    NSSet *set= [NSOrderedSet orderedSetWithArray:array];
    filteredArray = [set allObjects];

3) Concate String from array

NSString *myString = [myArray componentsJoinedByString:@","];

edited Aug 23 '13 at 12:20

answered Aug 22 '13 at 10:49

keen

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It would be nice if you added code for step two. Since everyone with a simillar problem probably dont know how to write it. – Jens Bergvall Aug 22 '13 at 11:07
You could have googled it, and found it very easily. http://stackoverflow.com/questions/5978574/removing-duplicates-from-nsmutablearray and http://stackoverflow.com/questions/1025674/the-best-way-to-remove-duplicate-values-from-nsmutablearray-in-objective-c – keen Aug 22 '13 at 12:13
- 1 Please add code for step two into the answer. You shouldn's assume people know, if that was the case you could assume everyone knows everything. Will add +1 when question is complete. – Jens Bergvall Aug 23 '13 at 07:26

score 0 · Answer 3 · answered Aug 22 '13 at 10:59

You can use NSMutableDictionary; In dictionary there are two elements; 1. Key 2. Value

Just set Keys as your array elements; Special point is that 'Key' can't be duplicate;

Now just get array of Keys by using [dictionary allKeys];

Now, at this stage you have unique values in new array;

NSString remove duplicated substrings

3 Answers3