ios - NSString 删除重复的子串

Question

如何从字符串中删除重复的替换？对于前。我有:aaa,bbb,ttt,bbb,rrr。结果我想要aaa,bbb,ttt,rrr(删除了重复的bbb)。我希望得到你的帮助。谢谢。

Answer 1

你可以这样做:

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] : @"";