ios - 如何在NSMutableArray中对对象进行分组并在Objective-C中划分为单独的NSMutableArray

我有这样的NSMutableArray：

// NSMutableArray *Data = (NSMUtableArray(NSDictionary))
       Data = {"Device": "A1", "Temperature": "25", "datetime": "2013.02.03"},
       {"Device": "A2", "Temperature": "25", "datetime": "2013.02.03"},
       {"Device": "A3", "Temperature": "25", "datetime": "2013.02.03"},
       {"Device": "A1", "Temperature": "25", "datetime": "2013.02.04"},
       {"Device": "A2", "Temperature": "25", "datetime": "2013.02.04"}.

我如何按照“日期时间”细分并将其分组到单独的NSMutableArray中。如上情况将分为：

Data_d1 = {"Device": "A1", "Temperature": "25", "datetime": "2013.02.03"},
          {"Device": "A2", "Temperature": "25", "datetime": "2013.02.03"},
          {"Device": "A3", "Temperature": "25", "datetime": "2013.02.03"}

和

Data_d2 = {"Device": "A1", "Temperature": "25", "datetime": "2013.02.04"},
          {"Device": "A2", "Temperature": "25", "datetime": "2013.02.04"}

最佳答案

如果您有这样的字典数组数组：

var data = [["Device": "A1", "Temperature": "25", "datetime": "2013.02.02"],
["Device": "A2", "Temperature": "25", "datetime": "2013.02.03"],
["Device": "A3", "Temperature": "25", "datetime": "2013.02.03"],
["Device": "A1", "Temperature": "25", "datetime": "2013.02.04"],
["Device": "A2", "Temperature": "25", "datetime": "2013.02.04"]]

然后，您可以根据以下任何键将它们隔离：

var dateArray = data.compactMap{ $0["datetime"] }
let uDateArray = Array(Set(dateArray))
var segregatedArray = [[[String: String]]]()
for dateTime in uDateArray {
    segregatedArray.append(data.filter{$0["datetime"] == dateTime})
}
print(segregatedArray);

  根据要求添加带有字典数组作为原始数据的Objective-C版本。


考虑您有如下的字典数组：

 NSArray *array=@[
     @{@"Device": @"A1",@"Temperature":@"25",@"datetime":@"2013.02.03"},
     @{@"Device":@"A2",@"Temperature":@"25",@"datetime":@"2013.02.03"},
     @{@"Device":@"A3",@"Temperature":@"25",@"datetime":@"2013.02.03"},
     @{@"Device":@"A1",@"Temperature":@"25",@"datetime":@"2013.02.04"},
     @{@"Device":@"X1",@"Temperature":@"26",@"datetime":@"2013.02.07"},
     @{@"Device":@"Y1",@"Temperature":@"27",@"datetime":@"2013.02.07"},
     @{@"Device":@"A2",@"Temperature":@"25",@"datetime":@"2013.02.04"}];

然后，您可以按以下方式将它们隔离：

    NSMutableDictionary* mutableDic = [[NSMutableDictionary alloc] initWithCapacity:1];
    for (NSDictionary* dic in array) {
        NSString* dateTime = [dic valueForKey:@"datetime"];
        NSMutableArray* data = [mutableDic valueForKey:dateTime];
        if(data != nil)//data with this key avalaibe, add further.
        {
            [data addObject:dic];
        }
        else//data with this key not avalaibe, make a mutable array with this dic and add.
        {
            NSMutableArray* newData = [[NSMutableArray alloc] initWithObjects:dic, nil];
            [mutableDic setValue:newData forKey:dateTime];
        }
    }
    NSLog(@"%@", mutableDic);

您可以根据任何密钥进行隔离，只需将该密钥放在[dic valueForKey:@"datetime"];即可。您可以按注释要求输入datetime代替Device。

隔离后调试器的屏幕截图：