Dictionary from an Array of Dictionary - Logical Challenge in Objective-C

Question

The goal is converting Array of Dictionaries into one Dictionary of different objects. How can I do that?

I have an Array of records in this format,

originalArray = [{
        "valid": "Y",
        "mof": "ON",
        "dof": "17-05-2019",
        "rtntype": "CODE1",
        "ret_prd": "042019",
    },
    {
        "valid": "Y",
        "mof": "ON",
        "dof": "19-04-2019",
        "rtntype": "CODE1",
        "ret_prd": "032019",
    },
    {
        "valid": "Y",
        "mof": "ON",
        "dof": "19-04-2019",
        "rtntype": "CODE2",
        "ret_prd": "032019",
    }
]

I want to create a Dictionary in the following format.

{
    "032019" = {
        "CODE1" = {
            "valid": "Y",
            "mof": "ON",
            "dof": "19-04-2019",
            "rtntype": "CODE1",
            "ret_prd": "032019",
            },
        "CODE2" = {
            "valid": "Y",
            "mof": "ON",
            "dof": "19-04-2019",
            "rtntype": "CODE2",
            "ret_prd": "032019",
            "status": "Filed"
        }
    },
    "042019" =  {
        "CODE1" = {
            "valid": "Y",
            "mof": "ON",
            "dof": "17-05-2019",
            "rtntype": "CODE1",
            "ret_prd": "042019",
        }
    }
}

Answer 1

Here is my sample, you can check by yourself

NSArray *array = @[
    @{@"valid":@"Y",@"mof":@"ON",@"dof":@"17-05-2019",@"rtntype":@"CODE1",@"ret_prd":@"042019"},
    @{@"valid":@"Y",@"mof":@"ON",@"dof":@"19-04-2019",@"rtntype":@"CODE1",@"ret_prd":@"032019"},
    @{@"valid":@"Y",@"mof":@"ON",@"dof":@"19-04-2019",@"rtntype":@"CODE2",@"ret_prd":@"032019"}
];

NSMutableDictionary *result = [NSMutableDictionary new];
    for (int i = 0; i < array.count; i++) {
        NSDictionary *dict = array[i];
        NSString *value = dict[@"ret_prd"];
        if (result[value] == nil) {
            NSArray *filterArray = [array filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"(ret_prd contains[c] %@)", value]];
            NSMutableDictionary *filterDict = [NSMutableDictionary new];
            for (int i = 0; i < filterArray.count; i++) {
                filterDict[filterArray[i][@"rtntype"]] = filterArray[i];
            }
            result[value] = filterDict;
        }
    }

NSLog(@"%@", result);

Result in console log:

Long time no code Objective-C, so above code maybe weird. Let me know if you don't know any where, I'll explain for you.