NSDiction的NSArray – 合并具有相同键值对的字典
我有一个NSArray的NSDictionary对象：
[ { id = 1; fromDate = 2014-04-03; toDate = 2014-04-05; date = 0000-00-00; title = title 1 }, { id = 1; fromDate = 0000-00-00; toDate = 0000-00-00; date = 2014-04-03 title = title 1 }, { id = 1; fromDate = 0000-00-00; toDate = 0000-00-00; date = 2014-04-04; title = title 1 }, { id = 2; fromDate = 0000-00-00; toDate = 0000-00-00; date = 2014-05-10; title = title 2 }, { id = 2; fromDate = 0000-00-00; toDate = 0000-00-00; date = 2014-05-11; title = title 2 } ]
我想将具有相同id值的字典合并到一个字典中，组合所有日期，fromDate和toDate键，获得这样的数组，忽略零值：
[ { id = 1, combinedDates = 2014-04-03, 2014-04-05, 2014-04-03, 2014-04-04; title = title 1 }, { id = 2, combinedDates = 2014-05-10, 2014-05-11; title = title 2 } ]
有人能指出我正确的方向吗？
除了基本的蛮力之外，我不知道有什么方法可以做到这一点：
-(NSArray*)combinedArray:(NSArray*)array { NSMutableArray* combined = [NSMutableArray new]; // Iterate over each unique id value for(id key in [NSSet setWithArray:[array valueForKeyPath:@"id"]]) { // skip missing keys if([key isKindOfClass:[NSNull class]]) continue; // Sub array with only id = key NSArray* filtered = [array filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(NSDictionary* evaluatedObject, NSDictionary *bindings) { return [evaluatedObject valueForKey:@"date"] && [[evaluatedObject valueForKey:@"id"] isEqual:key]; }]]; // Grab the dates NSArray* dates = [filtered valueForKeyPath:@"date"]; // add the new dictionary [combined addObject:@{ @"id":key, @"combinedDates":dates }]; } return array; }
// Group By id -(NSMutableDictionary*)combinedArray:(NSArray*)array { NSMutableArray *categories = [[NSMutableArray alloc] init]; for (NSDictionary *data in array) { NSString *category = [data valueForKey:@"id"]; if (![categories containsObject:category]) { [categories addObject:category]; } } NSMutableDictionary *categoryData = [[NSMutableDictionary alloc]init]; for (NSString *strCat in categories) { NSMutableArray *catArray = [[NSMutableArray alloc]init]; for (NSDictionary *data in array) { NSString *category = [data valueForKey:@"id"]; if ([category isEqualToString:strCat]) { [catArray addObject:data]; } } [categoryData setObject:catArray forKey:strCat]; } return categoryData; }