Question 244624 in Flutter Question posted in
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Flutter – How to you map your list data to accept a data from jsonDecode?

I’m trying to map a variable to receive data from my API through jsonDecode(response.body)

Here’s how I try to map, but I don’t know if this is correct or not.
The data from API.

    {
    "days": {
        "region1": [
            {
                "1": "2",
                "2": "Monday",
                "3": "25",
                "4": "10"
            },
            {
                "1": "1",
                "2": "Tuesday",
                "3": "21",
                "4": "12"
            },
       ]
   }
}

I want to have a variable to receive that data above.

  final Map<String, dynamic> listData = jsonDecode(response.body);

    for (final item in listData.entries) {
         print(item.days);
     }

How can I print out the days? or region1? how can I access to value Monday
I try this print(item.days) but it not work.

Tags:

2

Answers


  1. 0

    First, to access the "days" key in your JSON data, you can directly use listData[‘days’]. You don’t need to iterate through the entries for this specific case.

    Second, "days" contains a map where the keys are strings like "region1," and the values are lists of maps. You can access the "region1" data by using listData[‘days’][‘region1’].

    You can refer this one:

    final Map<String, dynamic> responseData = jsonDecode(response.body);
final Map<String, dynamic> daysData = responseData['days'];
final List<dynamic> region1Data = daysData['region1'];

for (final item in region1Data) {
  final String dayOfWeek = item['2'];
  final String value1 = item['1'];
  final String value3 = item['3'];
  final String value4 = item['4'];

  print('Day: $dayOfWeek, Value1: $value1, Value3: $value3, Value4: $value4');
}
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  2. 0

    To get the map attribute, you can use the property name inside the square bracket.

    final test = {"fruit": "apple"}
print(test['fruit');  => prints "apple"

    In your code, you can do the same.

    Example:

    import "dart:convert";

void main() {
  final data =    {
    "days": {
        "region1": [
            {
                "1": "2",
                "2": "Monday",
                "3": "25",
                "4": "10"
            },
            {
                "1": "1",
                "2": "Tuesday",
                "3": "21",
                "4": "12"
            },
       ]
   }
};
  
  final Map<String, dynamic> listData = jsonDecode(jsonEncode(data));
  print("Listdata: $listData n");
  print("Days: ${listData['days']} n");
  
  final List<dynamic> region1 = listData['days']['region1'];
  
  for(final region in region1){
    print("Day: ${region['2']}");
  }
}

    Output:

    Listdata: {days: {region1: [{1: 2, 2: Monday, 3: 25, 4: 10}, {1: 1, 2: Tuesday, 3: 21, 4: 12}]}} 

Days: {region1: [{1: 2, 2: Monday, 3: 25, 4: 10}, {1: 1, 2: Tuesday, 3: 21, 4: 12}]} 

Day: Monday
Day: Tuesday

    But, I suggest you to convert the Map into Models and access the properties. You can convert the json data to dart model from HERE

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